After a conversation on the topic of foldable bikes a few years ago with @stephanetavera, I was convinced to try one. Today, I finally rode a Brompton 6-speed, and I’m really impressed! A very comfortable bike that rides about as well as my current city bike, but fits overhead on a train or plane is quite a compelling offer…
@jack @stephanetavera mine's currently collecting dust, but only because I live in the sticks - can't wait to take it to the city (should have brought it to STL!). I have flown with it in carry-on a number of times, but permission/fit is a mixed bag. Would recommend a hard case, but that precludes the joy of riding to/from the airport. Trains, on the other hand... 
@blaine @jack @stephanetavera that's how I ended up with one of the Bike Friday quick-disassemble luggage/trailer bikes ;)
@palmer @blaine @stephanetavera These look great 
@jack @blaine @stephanetavera ya, I'm super pumped -- I got it from a friend who was too small for mine and I haven't really gotten a chance to use it yet, but hopefully it'll work out for the next round of conferences in a few months