I am delighted to report that in 2011, three years after the fact, that putting together a compact, powerful, and efficient electric vehicle drivetrain for local commutes (such as your campus, neighborhood, or urban area) using both R/C hobby hardware and specialized EV components is now cheaper and easier than ever. Price competition, new technologies, and just plain increased availability of fabrication and material resources means that building an electric personal transport device is now within the capabilities of just about everyone.
I will assume that you already know the fundamental parts of an EV or have built them before. If not, you're welcome to refer to my previous Instructable on this topic (linked above), or check out one of the many great Instructables on EV systems. This Instructable is intended as a conglomeration of resources, and so will discuss the pros and cons of component choices, specific vendors, design strategies, and other high-level considerations. It will also offer tips and tricks that I've found or had passed on to me pertaining to building small electric scooters. The guide will be overtly calibrated towards said scooters, since I favor them over electric bicycles, though much of the advice is just as pertinent to e-bikes. It should also be helpful for the occasional odd electric skateboard or other unconventional vehicle.
The format of the Instructable will primarily be a page or two on each primary component of an EV - such as the motor, controller, battery, and drivetrain (and associated mechanics).Then I'll present some designs that have emerged as being relatively easy to execute and fabrication advice for fully custom vehicles (i.e. not conversions).