Done it:

It's totally doable and the the bike rides really well. (Not to mention a great conversation starter)

Mine started off as a low end kids bike I picked up for $10. ( I later found it might have been a Formula One bmx).
I ripped everything apart, installed a euro bb converter, put on 165mm cranks and 451mm wheels.
Because my headset's inside diameter was 21.1mm (which a lot of bmx are), I had a really hard time finding a long quill stem. Finally settled on a quill stem extender.

It's really nimble, and not that different from riding a road bike. My longest ride was a 70km round-trip from Baltmore to Anapolis. A plus is I've packed it into a cardboard box within airline's regulation size, so I can take it on trips with me!