Yes, I was really sad when mine started getting gimpy (I tried to get some switches for it but none were available from Logi) - at least I haven't lost it. I'd be kicking myself every day if I had. I've been using the Logi Marble Mouse the only current approximation (it may have been discontinued too, but I grabbed a spare JIC). I can't see the logic in a wireless trackball, so I was never really interested in the follow-on to the original, but you may find some still out there...
. They still claim to have the MM at the Egg, but the shipping is ridic. @ ~$12. !!!
They have this other one:
http://www.newegg.com/Product/...x?Item=N82E16826104125 , but it is wireless and I'm sure it's not up to the original T-man FX plus it's not ambidextrous like the M-M. I often use mine with either hand (one little click in the Logi software and it's lefty in all respects) - I even learned to use the FX (one of the most righty-centric pointing devices ever) with my left hand. Necessity... You can get a better deal elsewhere than the Egg per Froogle.
All the rest are the thumb-ball design.
I see there are some FX on fleaBay - one is new in box w/ a starting bid of $170. or BIN for $230.!!! Used ones have bids in the $30.s... And Amazon has used starting at $75.
.bh.