Delays - what to do at Luton Airport?

Just found out that my flight out to Athens is going to be delayed about two and a half hours, provided it comes back from Istanbul without further delays... Of course that means that I will have to hang about in the airport (or should I pop back to the office after checking in?) for a long time and only get into the hotel at the other end around midnight.

Time to get the DS out for some brain training and Sudoku, me thinks.