My laptop keys get jammed up from time to time - spilt drink, crumbs from sandwiches & sausage rolls mixed up with dandruff and cigarette ash - I prise the key cap off and clean up the mess with an old, soft toothbrush and put the cap back on - it's a bit fiddly especially the first time and this link shows how it's done...
http://www.laptoprepair101.com/laptop/2007/03/20/key-fell-off-keyboard/
Good luck...
Peccavi
October 2009