Firmware Update problems

I was busy at my desk doing some schoolwork when I noticed that the updater icon was on my dock. Not fully paying attention, I briefly checked to see what type of update and it said it was an EFI firmware update I believe and I went ahead and okay'd it. Well, afterwards and after restarting, the gray screen for Lion comes up and I can do nothing else. Everyting I did to try and remedy the situation met with abject failure. Unfortunately it is out of warranty and since I am relatively new to MAC I am struggling a bit. Can anyone help? I would be eternally grateful!😕