This particular product is very big in the orthodontic community and has been for quite a while. Televox (http://www.televox.com) is one company to check out. Back in the day they sold orthodontists an expensive telephony board and their software used the doctor's own phone system to call all the patients. They now offer reminder calls as an online service.

There are many other companies offering the same services to orthodontists, Televox is just one that I'm familiar with as my customers use them.

So - whether you hate getting these sorts of calls or not there's definitely an existing market for them.

I played trombone through college (jazz band). Now I play bass and sing in a rock/blues band that gigs once or twice per month. I also hack around on guitar.