Has anyone tried a Streetstrider? looks like fun to me... http://www.streetstrider.com/
I also ordered my new trike today- i am soooo excited i can barely stand it. i was going to upgrade mine but decided to throw it up on craigslist and see what would happen. i sold it for what i paid for it 18 mo ago! i should get my new one in 2 weeks. And here's the truly exciting part- margie is actually developing some quads!!! :)
for any of you who have back problems, these recumbent trikes are amazing- i have no back pain riding this, and they are a blast. great company, and i've had excellent service from them so i like to pass on the word to others. http://www.streetstrider.com/