Will certainly be making use of my worn copy of The Way Out Tube Map. To those of you who've not come across this brilliant map I would say get one straight away. Basically it is a whole map of the tube but it tells you which carriage to sit in if you want to be nearest to the exit of the station you get off at. It is truly brilliant and has saved me walking half way or the whole way up a platform when I've been late for meetings. It is also highly impressive if you are travelling with someone and you say, "Oh let's just walk along a bit further up here, so we'll be near the exit on the way out", this only works if you've sneakily looked at the map beforehand and they will marvel at your knowledge of london and its tube exits.
Don't travel on the London Underground without it!