Depending on where you are you might be able to get a road legal one. Talaria and Surron have both sold road legal versions of some of their models here in Australia, I believe they've also done so in the UK and I did read something about some US states letting you register them once appropriate lights are installed.

Of course this does require you to treat them as a motorbike and keep off footpaths, have the appropriate licence, etc. Once you've got the licence you can ride other motorbikes as well though so I don't see this as a downside (it's an enjoyable method of transport and more people should do it).