5-a-side Football in London?

Does anyone know of any reasonably priced 5-a-side pitches in or around Central London. Trying to organise some football amongst some work colleagues, and am struggling to find somewhere!
Answers:
Theres a power league centre called "London City" near liverpool street station, (it's on worship street i think)

You can hire a pitch for an hour or join the leauge (£20 registration fee) and play every week in an organised league.

Me and my work colleague have a team and we're going all out for promotion this season!
Powerleague - Worship Street - off of Bishopsgate - £30 for the hour, 10 of you play that's only £3 BARGAIN!, They have lunchtime and evening leagues as well