I have a long (almost 5 hour) lay-over at Heathrow Terminal 4 on my way to Prague. Any suggestions on things to do while I am there? When I last spent time there in '97 I was bored silly since I am really not a big shopper. Anything new worth seeing or at least a decent restaurant/pub to hang out in?
I've thought about leaving the airport but even with the new express train it's at least 1/2 hour each way to downtown and I don't relish having to pass through security if I don't have to.