When it comes to designing a robot you can just jump right in and start building or you can figure out what it is you want to accomplish with said robot and design from there. The second method is generally preferable, although building for the sake of building sometimes can lead to new discoveries. For the You Design It project we pretty much have to go the route of figuring out what it is we want to accomplish first.
Rather than presenting a million different possibilities on what our completed robot will do, we will start with the method of locomotion, which should help us narrow down our possible purposes. For the sake of simplicity, I am presenting only the basic forms of locomotion that I can think of; some of these will require further decision making to determine the actual method used, sort of subclasses.
Stationary - a robot that does not change location on its own. A few examples would be robotic arms, tracking turrets and outdoor plant watering robots.
Wheeled/Roller - motor/servo driven wheels provide movement for this style of robot. This is the second most common method of robotic locomotion (stationary being the first).
Walker - the third most common form of robot movement involves a given number of legs rising and falling, or gyrating to push forward on wheels like a roller skater would. This would include bipeds as well.
Flyer - a robot capable of some form of flight or another, including hover-style motion. Limited hobby applications and more complex 3-Dimensional environment, but pretty cool stuff.
Swimmer - above and/or below water surface robotic motion that would present a variety of differing options on method of swimming. Like flying, this form of locomotion has limited hobby applications and a more complex 3-Dimensional environment.
Slitherer - snake like ground movement, which also presents the possibility of enhanced climbing capabilities within a larger 3-Dimensional environment.
Voting for the above topics will be enabled sometime on Monday, March 3, 2008. If you can think of a method of locomotion not listed above, please post a comment to let me know what I missed so I can include it. Keep in mind that teleportation is not a theoretical possibility at this moment. Bending space and time for warp propulsion is out of the realm of any hobbyist, instead think of something you would like to learn more on. Remember, the end result is to be a tutorial that other hobbyists can learn from and duplicate, not an experiment in complexity (although I do like making complex things simple). Happy voting.