How about a bit of reverse psychology (or whatever it's called)? Tell yourself that you're too busy and there is too much still to do and you're not tired yet etc etc and spend all night defrosting the fridge and doing the ironing and deep cleaning the carpets etc... make things up if you struggle to find enough to keep you going all night and really get stuck in to it all so that you don't have time to even think about sleeping... spend a couple of sleepless nights and days like that and you'll find that you collapse into bed in exhaustion and fall asleep because you are so tired.
Are you very creative? If you are, challenge yourself to bake and decorate a cake in the early hours or write a novella before midnight or paint/draw/colour a new piece of art before 2am or something like that? If you have any hobbies, spend the night sorting out your CD collection or researching something or studying a distance learning course etc.
Is there something you've always wanted to try but you keep talking yourself out of for whatever reason? Give it a go during the night while you're awake... post on forums, read emails, talk to people across the world from you etc... make use of the quiet times to do things just for you.
Hopefully if you try not to sleep, it'll just happen from pure exhaustion after a couple of days
