I picked one up from Amazon. Fits perfectly and I noticed a huge increase over my original battery. I went from 3-4 hours of heavy use to 6-9 hours of heavy use. Definitely worth the $12 (shipping included). I can easily go all day now with moderate use (3push email accounts, FB, Twitter, and Link'dIn all synced).
Current Phone: Nexus 4
Retired: GS3, HTC One S, HTC 8X, Galaxy Note, Galaxy Nexus, Lumia 710, HTC Radar, Focus, DVP, HD7, Sensation, G2X, Galaxy S, G2, Nexus One, HD2, Touch Pro2, N97 mini, Touch Diamond2, Touch Pro, iPhone, G1, Tilt, MDA, Dash, HP 6315, Treo 600
If you build it, they will flash.