See if you can release the calipers in the same way you would do so when doing a brake job. Wedge a long screwdriver into the opening in the caliper so it lodges in the vents in the rotor. Dont press against either outside surface of the rotor (will damage surface). Then pull towards you to force piston back in and hopefully free up calipers..... however, you don't specify man/auto. If its a manual and you've had your e-brake on the whole time, I would agree with hockeyfan27 a good place to start would be the e-brake.
DCT Electronic Shifter
Bilstein and H&R sports suspension, Rogue Enginerring Race Brace
AA Stage2 tuning
Conforti CF Cold Air Intake
Hamann Front Spoiler and Side Skirts
BMW OEM rear wing spoiler.
M3 SMG Paddle Steering Wheel and M3 Seats
18" M6 custom painted wheels
Custom red kevlar interior
VIS CF Hood