Beginning Jan 1st, 2006, residential and businesses that install them may also qualify for a 30% federal tax credit.
The fed tax credit is a max of 2k for residential and NO LIMIT for businesses!
In Austin, in addition to that, Austin Energy rebate pays between 45% and 75% of the cost of a solar system.
If your electric company has not informed you of this in a flyer with your bill, and has a website for more info, then they SUCK!