Hey no0n3 - I hadn't heard of that one. I *did* take a Bike Friday Tikit out for a test ride and really liked it. It folded up quickly, was quite sturdy and very quick. Price wise, though, it was not on the lower end. The handling of a bike with 16" wheels is something that takes a bit of getting used to. At first it felt way too sensitive though after a few minutes I adjusted to it. I think its "twitchiness" could turn into agility when one got a bit more used to it.
A friend of mine has the Dahon Curve and really likes it. It's quite a lot cheaper than the Bike Friday one (but still not cheap). My daily rider is a Dahon folding bike - a big one with 26" wheels so it is effectively a full-sized bike I can take on business trips). I *really* like it. Good workmanship, very quick, fun to ride.