Bike Fridays can also be quite a bit lighter than most other folders that I've seen. I lifted a folder at Performance last weekend, and it was a tank. Same for the ones sold at West Marine marketed towards boaters. My little Bike Friday Pocket Crusoe (in the "petite" model) when I take the rack and other junk off her, is not much heavier than the carbon road bike I sold last year. She has Ultegra and XT components, and you can have one built with even lighter Dura-Ace components for a hefty sum. The less expensive folders typically have much lower-end components.

In less expensive folders, I've read lots of good reviews of the Downtube Mini, and while not quite as light as some models of Bike Friday, it is relatively light for a folder and can be had for a lot less $$.

Good luck in your search.