In reply to colinakmc:
'I think pretty much everything flat.ined between 2008 and about last year'
The FTSE 100 index is roughly back where it was at the start of 2008 (by the end of 2008 it was down 31.3%). However, the constituent companies paid dividends in the intervening years, so if you'd held on to an index tracker for all of this period you would be appreciably ahead.
Of course the smart thing to do would have been to sell at the start of 2008 and buy again at the end - myself I underestimated how steep the fall was going to be and didn't sell until my holdings had lost more than 20% of their value.
For what it's worth, I'm sufficiently worried about the possibility of Greece leaving the euro to have sold 90% of my shares this morning - if Greece does leave the result could be devastating for the stock market. This also ties conveniently into a 'sell in May' strategy, which has been pretty successful for the last few years.