I had to take a trip to London, Oh what a shame!
When I was working in London last year I always went past this place that looked amazing from the outside, I was right it is, great tea, great cake and you can get your bike fixed while you wait! They also offer free wifi (yay) it's called 'Look Mummy No Hands' http://www.lookmumnohands.com/and its on Clarkenwell Road.