Should have mentioned that for any US Dollar investors contemplating UK investments I'd suggest perhaps holding off for a while yet.
'Quantative easing' - or printing money is likely to drive the USD/UKP more closer to parity over the next year or so IMO.
It's a bit of a race as to who prints the most, my guess is that as we're in more of a bad state than the US that we'll win that race.
Get the timing right and you'll perhaps be able to benefit from a good yield and currency benefit (I believe historically long term the pound/dollar has typically ranged from near 1:1 up to 1:2)
You get the impression that stock prices progressively rise over time.
Looking back further however reveals that hasn't always been the case
What appears to be consistent across time however is that generally stock capital gains average out as barely beating inflation and its the dividend income benefit that provides the 'risk premium'. Buying as much of that premium for as little as possible (e.g. when yields are relatively high) is likely a good thing.