I just put my mind to doing something else and that tends to keep me awake most of the night.
Usually atleast until it's getting light outside.
This ranges from simply browsing the internet all night, to playing videogames and then there's reading.
I can easily get carried away with reading and read through the night.
It's enjoyable, but it's a bitch to try and get to sleep as the room slowly gets brighter and brighter.
And a fizzy drink can help too.