When I have had that problem I loosen the lug nuts slightly then then drive aroud the block very carefully. It helps to make some turns.
I will not recommend this though because of the obvious safety concerns.
If the wheels are stuck, you are going to have a real job ahead of you on getting the rotors off.
I use anti-sieze lightly between the rotors and hubs and between the rotors and the wheel to keep this from happining. There is still enough anti-sieze remaining to be effective since the last treatment 50,000 miles and ten tire rotations ago.
