There was an article a few months ago about how taxis in Amsterdam (or was it Copenhagen? One of those super-bikeable cities) started carrying bike racks, and they were a huge hit. That way you can move around on a bike, go to a bar, and get driven back with your bike.
I'd love to have the option of putting the bike on a cab if I had a mechanical problem that I wasn't equipped to solve while on the road. Or if you bike "too far away" and need to come back (or if you need to go very far away and you'd like to bike the last stretch...).