$50 is way too much for such a little increase in battery life. I bought these:
http://cgi.ebay.com/ws/eBayISAPI.dll...fvi%3D1&_rdc=1
I haven't received them yet. I'm not expecting too much from them. If they last only a few hours I'll be happy. I'll only be using them in an emergency if my original batt runs out of juice. Plus they come with a charger. For only $15.99 I say what the hey. The worst that could happen is that my phone explodes.