Sadly, despite the high increases to date in food and fuel, most analysts think that we're unlikely to feel the full effect until 2009 for several reasons.
Firstly, existing inflationary pressures (on food and fuel) are here to stay for a while yet - they're driven by global factors (especially increasing demand in Asia) which the UK is largely powerless to do anything about in the short term.
Secondly, they're yet to fully feed through into other sectors - gas providers, for example, are affected by the cost of oil but the impact on gas prices takes a couple of quarters to have an effect; gas companies are now putting in place 40% price increases to reflect their higher costs which will come in through the next year. I'd imagine electricity providers will do the same.
Thirdly, given that people are generally on fixed term mortgages, a lot of people haven't actually been affected by the credit crunch yet (which only really started Q3 2007) - as people come to renew their mortgages over the next 18 months, that's when they'll find that either mortgage rates are much higher or they can't get a mortgage at all. This will also feed through into the rental market in terms of higher rents to meet the landlords' higher mortgage payments.
Fourthly, very very few people (so far) are in a meaningful negative equity position as house prices have only been sliding for the last 6 months after several years of sustained growth. If they continue to fall as predicted, and credit availability continues to be limited, then negative equity will become much more meaningful much more quickly.
Fifthly, unemployment remains very low by historical standards. It's going to go up, especially in the sectors which are being directly affected (e.g. construction). To cap off an already shit situation, more and more people are going to find themselves out of work.
It's pretty scary, especially how it's affecting the essentials (food, fuel and housing). On the plus side, if you care to see it, it's probably not going to be as bad as everyone fears, i.e. like the 1970s. Inflation is higher than expected at 4% this year, but it's still a drop in the ocean compared with the 25% back then (it's also lower than in other countries). Ditto interest rates which absolutely wiped out the housing market last time - currently 6% vs. 15%+ last time. Plus in the absence of heavily unionised industries, there's unlikely to be a repeat of the wage/ price spiral which sent inflation through the roof.
Personally, I'm trying to get all credit cards paid off as quickly as possible as those rates will be definitely going up and will also see what the deal is on refinancing any outstanding balances (e.g. with lower cost bank loans). I'm also having a look around to see who's doing the best deals on gas/ electricity and seeing if I can lock in any prices - even if I get a bit screwed on the margin, at least I can budget around a known cost rather than get exposed too much.