I don't know if I'm supposed to suggest apps here or not, but there is an app called Setting Profiles on the Market that is fantastic (Amazing.) It will allow you to build conditions to trigger any profile that you would like to set up. I use it to trigger WiFi when I'm at the house, put the phone on vibrate when I'm in a meeting, silence the phone when I'm at church, the list goes on... It is a paid app $2.95 on the market and worth every penny.
Today in my Calculus class I stumbled upon one of the greatest apps yet. Its called Handycalc and its a full functioning graphing calculator plus more. Definitely check it out if you need any type of calculator app.
Currently Sirius/XM have an iphone app and I believe a Blackberry app is either just out or will be soon. I have got to think a Droid app is forthcoming. Same with ESPN and a few other big time sites...They may have underestimated the Droid's popularity & awesomeness!
I can't wait for the Sirius/XM app for the Droid although I have read reports that channels like Howard Stern will not be available on phone apps!