Tried Birdies while staying in Paris for about a week last October. It was so much fun, although depending on the distance you need to cover - not exactly the cheapest one. We actually brought our bicycles with us to move around Paris. Used them once, then tried Birdies just for fun - and that's it, we fell in love with them, bicycles were forgotten for the rest of our stay. Again, this is not one of the cheapest joys depending on the length of the ride, but for really short distances combined with lots of fun – it's worth it.
Looks more like a scooter, but you end up riding it more like a skateboard. You never have that feeling like the throttle or brake is gonna rocket the board out from underneath you because you have something to hold on to. Also the controls are built / wired into the handle, so you never have to worry about losing wireless connection to mission-critical functions like your brakes...