Im a graduate with an idea for an online game which is very simple and I think very likely to be big. I need a programmer though as I have no idea how to create my idea really well. Does anyone fancy a hobby???? or can offer any suggestions how I could go about finding a company to create the game?

If you're just making a game for fun, perhaps you should find some Open-Source programmers who like to make Free Software. There might be someone hanging about on irc.freenode.net .

If you're serious about wanting to make the game into a commercial venture, make sure some company doesn't just steal your idea without reimbursing you. Make sure you write it down so you retain copyright.

make a project on sourceforge, write some ideas down and then try to recruit people

There is such game in undernet (irc.undernet.org) and it is called idlerpg you can take a look in the channel #idlerpg very kewl game