http://www.kickstarter.com/projects/842248593/roll-out-the-elf-to-your-city My son produced this video...
Seems nice! My knees are shot, though. I wouldn't be able to ride one. What about using the battery to power the wheels? How does the break operate? What is "legally go anywhere a bike goes" ? Doesn't it depend on state laws?
Probably relies on local laws as well although I seem to recall my son telling me that this guy started working on this in CA, I think.