Our local councils get these awesome little electric golf-cart things to roam around servicing things, but they're not legal for us to own, which is a real shame.
Something the size of a golf cart, so it can be tucked away in a corner somewhere, or parked sideways with tail to curb and be no longer than the standard width of a parking spot, would be absolutely incredible. It would only need ~20-30km range, seat 2, and have a small area for storage, and I truly think it would be pretty popular for inner city dwellers. Most people just keep a cheap car tucked away in a back street nearby, or use Vespa-style scooters.