any ideas on cheap train / coach / bus tickets for traveling to london?

we are three very skint students who need to get to London!
unfortunately most of the sites which offer cheap tickets seem to only be for travel in three months time and we really need to travel this month or early next.
any help would be greatly appreciated by us and our student loans!
thank you very much xx x

Where are you travelleing from??
I would suggest National express for a bus and the associated Eurolines...see links