This was in the paper a couple of days ago. Those of you looking for flats may find it helpful. It was complied by an Estate Agent and is the average rental rate in GBP/month as of April.
1 Bed 2 Bed
Clerkenwell 1700 2300
West End 2000 2600
St. Johns Wood1500 2000
Hammersmith1350 1600
Battersea 1300 1500
Blackheath 930 1300 Islington 1500 2000
Barnet 725 950
Kentish Town1100 1420
Shoreditch 1400 1800
Hackney 850 1120
Surrey Quays1050 1230
Wimbledon 1400 1700
Tooting 900 1150
Unfortunately, the point of the article was that while housing prices are falling, rental rates have risen year over year.