bought a 1500mAh (OEM TP2) battery from ebay, came recommended from another forum (androidforums.com i believe). It may only be 200 mhA larger than stock but it was only $15 dollars and for what i paid it gives me a few more hours of use, i could not justify spending $50 on the seido one. Anyway, here is the link to the ebay store i got it from.
http://cgi.ebay.com/OEM-ORIGINAL-HTC...#ht_2939wt_911