On the latest board I think its around 19 or 20.

If you need to control more than that, say... like 48+... you can purchase a Mux Shield from SparkFun to plug into the top of the EZ-B. Well, you can't at the moment as I see they're currently back-ordered - although you can sign up to be notified when they get more in. Excellent little shield to have on hand should the need arise...

radmeck you know you can get them from Solarbotics right? I just got mine yesterday after only 3 days of shipping. And it was only about 5 days ago I found out about the EZ-B.

Do you have a link for it? I don't think I've seen the Mux shield at Solarbotics before...

Oh not the Mux Shield. Sorry I should have specified Solar botics does sell the Propeller servo Controller USB, but I am not sure if its compatible...