So, I build a dock into my bag and wired it through to an inner pocket where theres a portable battery. Now, whenever i slip my iPhone into that pocket, it gets charged!!
Step 1: Buy all the crap you need!
then, the awesome part is the tekkeon (i have no commercial relationship to them, just a happy customer!) rechargeable mobile power unit, purchased for $36.95 on newegg.. basically, its battery pack with a 4,000 mAh capacity (iPhone's battery is 800 mAh i believe) that outputs power to a usb port! perfect for the iphone!
obviously, you need the sync cable, and the iphone itself.
oh, you'll also need some krazy glue, or other adhesive that works on plastic.. might wanna get a sharp knife too..
Step 2: Hack the crap out of the universal adapter so as to fit the sync cable through..
1) took a knife and shaved the sides of the sync cable, then
2) melted a bit of the hole in the universal adapter so as to fit the sync cable through.
3) krazy glue both parts together like crazy until theyre solidly affixed!
it looks like crap, but considering that part remains hidden we're going for function over form here..
when it fits through, and try to get it as flush as possible---
if the cable isnt through far enough the phone wont connect well enough to charge, and if its too far through it'll be hard to get the phone to lock in easily..