I got a few PMs asking about the battery box, so I thought I'd post details here. I've used two models of box so far, the Pelican 1300nf, and the Pelican/Hardigg im2075 storm case, both @$35 on ebay. Pelicans make great battery boxes because the are super-light, super-durable, and easy to dremel and drill.
I use 'weight clamps' or 'accessory clamps' to mount the Pelican boxes to the stanchions of RockShox Boxxer forks. Boxxer stanchions were 32mm/1.25" until 2010, when they went up to 35mm. The clamps are designed to mount lead weights on tube-frame race cars. They have holes for the .25" mounting bolt. The vendor for these particular clamps is Wehr's Machine Racing, here is the auction where you can buy them:http://cgi.ebay.com/ebaymotors/ws/eBayI ... 0344689577
The entire assembly weighs only 4lbs, mounts securely, and offers the protection that soft-sided prisimatic cells need. The 1300nf will hold (20) a123 16ah Prisimatic cells (1kw), and the im2075 will hold (260 a123 Prisimatic 20ah cells (1.5kw). Since LiPo is 50% volume of the Life, you could fit twice as much capacity into the box; since it still weighs 85% of the LiFe, you would probably want to add more clamps for the extra weight.
Here is the post in the build thread that has lots of pictures. Note the (2) dead-simple but stealthy power switches, one has a resistor around it to pre-charge the controller:viewtopic.php?f=6&t=24329&start=30#p470443
I did earlier builds with ammo boxes too, which are much heavier and more difficult to machine. I've also use larger clamps with .50" bolt holes, but they were much heavier so I would avoid them too.
With the weight over the front wheel, it always stays planted. When I turn my handlebars with one of these boxes, the battery mass is directly connected to them so steering input is instant. When I turn handlebars on a rear or triangle-mounted pack, that steering input has to translate through the frame to the battery mass, flexing and slowing responses. I first discovered this on my xtracycle, which has a 5304 and 30lbs of LiFe on the back, so steering inputs are more of a suggestion than an imperitive.
Suprisingly, it is pretty easy to lift the front end on jumps.