Switching to the Euro would make things slightly easier but so long as the ATMs work, it's no hassle using the Nationwide Debit Card. As for the Drachma - I'm all for that. Prices were significantly lower before the Euro. I remember the first year after Euroisation :'( we saw some Ouzo in a petrol station shop still priced in drachmas - under 500 for 1/2 litre. The attendent converted it to Euro and we got a bargain (two actually).
Of course it would be more convenient for foreign travel if the UK adopted the € but the main point is that there seem to be sound economic reasons to keep the £. I'm sure the majority in the UK would vote to keep it.
In the resorts I went to in 2002, when I think the € currency went into circulation, there wasn't a noticeable increase in prices from the previous year. However, when the Greeks were using drachma I remember how much prices went up year on year. So the € has introduced financial discipline into Greece.
Mike