Winter lighting for tightwads

I need a night light for my mountain bike for the ole winter training. I've the following considerations:

- I'm a total tightwad
- I might want to use this on a few bikes
- I walk/run too so want something flexible
- I've a load of gadgets in my gaff that use rechargeables, so I've invested in some high quality batteries, I'd like to use those if poss.
- I really am a tightwad

Dedicated mtb setups look lovely, but they're blooming expensive, like £200 plus, but that could be for good reason. I've never done any winter mtb'ing in the dark, and I'm sure others have tried to shortcut this so I'd like to draw on any wisdom if there's any out there?

I think I'm being clever by coming up with the following. A torch like this or even two:

http://www.thetorchsite.co.uk/LED_Lenser_Professional_AA_Cell_Torches.html

Rigged via some recycled tubes and a bit of luck to the bars, like so:



..equipped with some high qual AA's should fit the bill and be loads cheaper and more flexible than a dedicated lighting rig.

But if it's that easy, everyone would do it, right? :)