What helps you do something, when you have no motivation to do it?

I am currently suffering from a bad case of senioritis. I have lost all motivation to do anything school related. I think because it is all so stressful I want to avoid it all together, which as you can imagine is not the best solution. So, jellies what gets you motivated? How do you give yourself a kick in the pants to just get something, anything done? HELP!