How often do you use that “B” setting on your camera? For many photographers, going there goes hand in hand with stepping out of the comfort zone. In my opinion, that's one good reason to do it, because most creative breakthroughs tend to happen outside of your comfort zone. The other reason I like to set my shutter speed to Bulb is that there are some really awesome things that can be done simply with long exposures. If you're not using it, here's a little bit of inspiration.
Lighting Shots
Contrary to what some inexperienced photographers believe, you don't need a sophisticated sensor or trigger to photograph lightning strikes. What you do need is a tripod, or better yet, a tripod alternative. I also prefer using a remote shutter release, but you can get by with using your camera's delay if your setup is good and solid. Oh, and it should go without saying that electrical storms are dangerous, so you'll need a little common sense.
The procedure is simple. Use a normal or wide angle lens. (Your 18mm-55mm kit lens will do just fine.) Mount your camera solidly and set your aperture to f/11 and shutter to “B”. Set your focus to infinity and take a test shot to confirm focus. Aim in the general direction of the active storm cell and take a series of exposures, opening the shutter for about 4 seconds at a time. Make adjustments as necessary.
Light Trails
There are dozens of ways to photograph light trails. The most common is probably cars on highways, city streets and bridges. You can also consider ships coming into harbors at night and planes landing and taking off. Once again, be sensible about your personal safety.
The required equipment and starting settings will be roughly the same as above. You may need to adjust exposure times according to how much light is in the scene from other sources (street lights, buildings, etc.). There's a lot of room for experimentation here.
Moving Water
This one is a favorite of many landscape photographers and an awful lot of fun. Those dreamlike effects caused by shooting moving water at slow shutter speeds are very unpredictable and often pleasantly surprising. You will, however, need to add a Neutral Density (ND) filter to get these shots, because you'll be shooting in daylight. The more dense the filter, the longer your exposures can be.
Exposure settings will vary according to the conditions, your filter and the results you want, but the settings we used above are a reasonable starting place. Because the filter is very dark, you'll want to stabilize your camera, lock your focus in, then carefully mount the filter before you take the shot. Try starting your exposures at about 1 second with a medium density filter, and extend the time with darker filters. The longer the exposure, the more vague the water will become.
These are far from the only things you can do with your shutter in Bulb mode. Light painting, deliberate camera vibration, fireworks – possibilities abound. You've got to go there to get them done, though, so get out there and try the “B”.