My Fiancee and me were traveling to London. It was her first time so we actually looked at all the touristy things but on top of that Jon had great ideas to explore london a little bit more of the beaten track as cheesy as it sounds. Jon provides a great (as far as I can tell) selfmade cityguide. Jon is a very good communicator, easygoing and even asked us if we wanted to have breakfast at his place.
Definitely a recommendation on our part!