I am now up to being able to practice for about 45 minutes before my muscles give out. Ran a bunch of scales today, then played around with a book of simple jazz arrangements for a while just for fun. The book came with a CD of backing music, sort of a saxophone karaoke CD. Such a thing didn't exist 25 years ago, and it is a lot of fun, although right now I'm just playing solo--I don't think I'm ready to sync up with a CD yet. I've also been enjoying doing simple improvisations with no accompaniment. This is something I do all the time, either humming or whistling, while I'm working. I still have a long way to go before I can get the music in my head to come out of my fingers as flawlessly as when I whistle, though.
To finish, I let both kids honk on it a couple of times while I played the keys. They thought it was great fun. My daughter has declared she wants to play sax when she is able to start band next year.