Pragmatic Prose

I want a phone that I can script/program/hack. For example, I want to be able to have the ringer volume change at a scheduled interval.  I work in a quiet office from 9AM to 6PM.  So during that time I'd like the ringer to go to vibrate.  However, outside those hours, I'd like to the phone to go to full ring volume.  

I can probably program something like that but then you have to pay money to the cell phone company to get it on your phone.  I just want it on my phone, I don't even really want to sell it.  I could be convinced to sell it, but I wouldn't have to.

Anyway, if anyone could point me at a good phone (or carrier) that lets you script some simple actions on the phone without having to pay an outrageous fee, I'd appreciate it.

I know there are SDK's and API's available.  That's not the problem.  It's actually deploying the app on my phone.  Right now I have an LG Dare and Verizon.  AT&T is coming to our area this year so I suppose I could get and iPhone and jailbreak it, but I'd rather not.