[JamesD]

I know quite a few people have looked for these in the past for fingerboard work, these seem pretty well made and cheap for what they are, plus the weights are easily removable:

http://www.sport-tiedje.co.uk/kettler/nylon_gewichtsweste.htm

[Mike Tyson]

Good find, cheers.

Fancy buying me one as I am broke? 

[JamesD]

By the way the same company also do really cheap doorway mounted pull up bars, for around £17 that can take a load of up to 150kg apparently, therabands, and a multitude of other equipment.
Although not sure how their prices compare to other companies on the therabands?