Fellow Gibbetd digger speleotramp put me on to this.... 2AA cell Tesco LED light with wat i believe is a 3 Watt Cree in it... not regulated, but for ?8 is very impressive. O-ring seals everywhere except the switch on the base, but think a pvc glove-finger and a cable-tie would waterproof this well.. for a review (of sorts) look at : http://www.aditnow.co.uk/community/viewtopic.aspx?t=1956 

I think I might have actually seen this on the forum, but the single AAA LED waterproof light from 7dayshop is very very good - ?2 in single items, ?1.50 / unit for >10.

Twist bezel, o-ring on neck (could do with substitution with thicker o-ring and grease for diving applications), high-impact plastic case, electronics in head nicely open so you can check for corrosion.

Beam throws quite nicely (perfectly circular), with smooth tail off at edges, standard bluish LED tint. Nice high viz yellow case.

Closest 'real' torch I have to compare it against is the UK 2AAA Xenon dive torch.
The UK 'seems' about twice as bright, case more sturdy.
But it does cost 10x as much

I've got a couple of Tesco lights, they are definitely brighter than my Oldham.......

Moonbeam reflections on muddy hessian are brighter than an Oldham.

My Oldham was always brighter than everyone else's NiCad conversion, until it wasn't and then I converted it to run on NiCad's.  :

See:
http://ukcaving.com/board/index.php/topic,6772.0.html
for more on the Tesco torch.