I used to just check out local places that had flyers up - boxing, circuit training, mixed martial arts... Gerenally paid about a £3-5 for a 1-2 hour session. Recently found a nice place/dojo hidden away run by an old Japanese master and photos of the same place from the 70s, which gave it a cool sense of history. :P
Some places were more dodgy than others - didn't want to go just to get beaten up heh. Best places were at my local university who catered for non-students too.
The way I see it though, if you can really be arsed to get into shape, then its easiest/cheapest to just go out for runs or play sport with friends. Gyms are a waste of time and generally extortionate, especially if you rarely go and end up paying every month!
Difficult to find time these days, but just started playing football (or soooaacceeer as you guys might call it!) every week after work on a Thursday. You know that feeling after a game and its been a long time since you played last, when you get an aching muscle in some random part of you, where you didn't think you would even need one? Strangely satisfying.
Theres a nice 5-a-side outdoor pitch nearby at the local college - 20 or 30 quid for 1-2 hours, but split between 10 people and its not much.
<message edited by choupolo on May 12, 2009 23:32>