Andrew
Can't speak from experience yet, as my new scope is still on order (long story, don't get me started), but...
I have purchased DeepSky 2000. While a bit ugly UI-wise, it is great for planning onserving sessions. It has an ASCOM driver, and also a PocketPC version included. I have ordered a bluetooth adapter for the scope, and in theory, I will be able to plan on the PC at home, download to the PocketPC (my phone), and then control the scope from the phone via bluetooth.
At least, that is the theory!