Some top tips there Guys.
It's a great shame you don't have more time, 48 hrs in London is not even going to scratch the surface.
NFS's tip for the Dover Street bar and Cafe is a good un.
Covent Garden is a must IMO, you can spend a good few hours there just watching the street entertainers + you have a fair selection of shops,bars and restaurants.
Clos Maggiore' s restaurant is a good one.
Navajo Joe Bar & Restaurant gives you it all, especially if you like Tequila!
What about a show in the West End,have a look see,you must be able to find somat here:
http://www.officiallondontheatre.co....eland_0907.pdf
Greenwich has a good market on Sundays,bit far from Kensington though,the water taxi is a good way of getting around as well:
http://www.thamesclippers.com/home/
Best of luck and congratulations.