The main reason for using a remote shutter release is to prevent accidentally bumping and moving the camera during longer exposures (well, I suppose also for times you want to include yourself in the shot). You can accomplish something simlar with the self-timer.
I don't know what connectivity your camera offers.
There are wireless remote releases that need to be directed toward the front of the camera (the thinking is probably that these are for self portraits, but with care they can be used for other types of shots, I'm sure). The RC-6 is one of these, using IR for connectivity (so it needs line-of-sight with the corresponding sensor on the camera) that seems to work with most Canon cameras.... probably yours included. It's quite small and simple to use.
There are also wired remotes, which are more what I would refer to as one of the "release cables" you are asking about, although modern ones are electronic controls or switches, not mechanical cables the way they were with vintage film cameras.
With my cameras I use the Remote Switch RS-80N3 and Remote Timer/Switch TC-80N3. The RS-80N3 is simply a shutter release switch. The TC-80N3 is an "intervalometer" that can be programmed to take repetitive shots at set intervals, such as for time lapse photography, and also can be used as a simple remote switch. Both these use the "N3" socket on my cameras (the "80" refers to the length of the wire lead, in centimeters). I may be wrong, but I don't believe your T3i has an N3 socket, so I suspect it can't use these particular release switches.
I'm pretty sure your T3i uses an RS-60E3 wired release switch instead, which has a completely different type of connector. If you want a wired shutter release, look into this one. Just confirm it's compatible with your camera. I don't believe there is a Timer Switch ("TC") version of this release, but you might search for one anyway.
One advantage of the wired release switches is that they can be used from anywhere around the camera, even behind it. This makes them less useful for self-portraits, of course... But probably more useful for everything else where you might want to use a remote release.
There are also third party radio transmitters and receivers that can be used as wireless remotes. Often these also can be used to fire flashes remotely, too (flash might only be usable in manual modes, though some appear to offer more complete ETTL control).
As far as I know, Canon doesn't make any radio remote releases (Canon has within the past year begun offering the radio controlled 600EX-RT flash and ST-E3-RT controller module, which only serves for flash control as far as I know). I haven't really shopped around for any of these, if interested you'll have to.do some research for models that can be used to trip the shutter and are compatible with your camera.
Some other tips you might find helpful...
Since you are thinking of making long exposures, another thing you need to be aware of is "mirror slap blur". This is slight vibration within the camera due to the mirror flipping up out of the way and the operation of the shutter itself. It can cause image blur at certain shutter speeds. Usually this can be a concern between about 1/30 or 1/15 and up to 1 or 2 second exposures. Shorter and longer exposures are less effected or unaffected by it.
If you find yourself shooting in that range of shutter speeds (say 1/30 to 4 seconds, to be careful), there are a couple ways to minimize the chance of vibration blurs. One is "Mirror lockup". This is a feature in the menu of most Canon cameras (you'll have to look up how to use it in your T3i). In most cases you can enable it for just a single shot, or you can enable it to operate on every shot taken until you go back into the menu and disable it. When mirror lockup is enabled, you have to press the shutter release twice to take a shot: once to raise the mirror, and then a second time to release the shutter and actually take the shot.
Another, more modern way to accomplish pretty much the same thing is to use Live View. When you use Live View it raises the mirror and opens the shutter in advance, as soon as you switch the camera into LV mode, so that you are actually viewing the scene via the camera's imaging sensor. Then you just need to press the release any time you're ready to capture the shot. You can even take multiple shots, if you wish. Be aware that auto focusing with Live View uses a completely different method than usual and is noticeably slower. But shooting scenics such as landscapes and cityscapes this shouldn't matter very much.
Also, regarding focusing for scenic shots, do an online search and read up about "hyperfocal focusing distances" and learn how to use that. You might want to autofocus the lens, then turn off AF to lock the focus in place, so that focus doesn't accidentally change when you press the shutter release. Back Button Focusing is another way to do this, separating focus from the shutter release so that you don't have to manually turn off AF on the lens.
Often for scenic shots you want a lot of depth of field (DOF), which can be achieved by stopping your lens down.... Just don't stop it down too far. Use f8 to f11 max. Any smaller than that, an effect called "diffraction" starts to occur, that actually robs fine detail from your images. Learn how to do depth of field preview with your camera, to best choose an appropriate aperture and utilize hyperfocal focusing distances. (NOTE: I just looked and see that your camera has A-DEP or Automatic Depth of Field setting.... I've used this on other cameras in the past and found it to be okay, but it tended to give a somewhat more than was needed, which can result too small apertures, too slow shutter speeds and/or too high ISO. Particularly shooting at night, I recommend just learning to set it yourself, using hyperfocal focusing, DOF preview and gaining your own experience with various apertures of your particular lenses.)
You'll have to try to balance using a smaller aperture for lots of DOF off against keeping to reasonable ISO settings and fast enough shutter speeds.
Depending upon your workflow, i.e. how you take and process your images, you might want to turn off Long Exposure Noise Reduction in your camera. When you use this, your camera will actually need to take two shots for every image. The second is a "blank" shot made with the shutter closed, that the camera uses to identify noise to be subtracted from the actual image made with the first shot. The second shot has to be the same duration as the first. So, for example, if you take a 15 second shot with LENR turned on, you'll need to trip the shutter a second time for another "blank" 15 second shot. IMPORTANT: If you fail to take or cancel the second image before it's complete, such as by turning off the camera, both images will be discarded. Keep this in mind, if using LENR.
If shooting lone exposure JPEGs, you are more likely going to want to use LENR. Image quality may not be very satisfactory if you wait and apply noise reduction to the images later. If shooting RAW files instead, you might wait and apply noise reduction later during post-processing on your computer, during the RAW conversion. So shooting RAWs you are in better position to turn off LENR.
Like previous responders, I also would strongly recommend taking at least a compact tripod, if you hope to do longer exposure shots with your camera for some cityscapes at night. However, as brightly lit as Vegas is, you may find shorter, handheld exposures possible with 1600 or even 3200 ISO. Keep in mind that long exposures will blur any and all movement of cars and pedestrians... Really long exposures will only show "ghosts", or moving objects might even disappear. This can make for weird, abandoned looking cityscapes.
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Alan Myers
San Jose, Calif., USA
"Walk softly and carry a big lens."
GEAR: 5DII, 7D(x2), 50D(x3), some other cameras, various lenses & accessories
FLICKR & PRINTROOM
so for those who haven't read any of my threads (i've been posting quite a few lately 
) ive recently bought a t3i and i've always been interested in landscape photography, so i was recommened the 10-22mm lens. i should be receiving it soon by the way!
and the actual reason i've started this thread was because i needed opinions on whether or not i should buy the canon remote switch rs60 e3? or should i just save money and just use the self timer?
