Better late than never...got this Evo 4G extended battery and replacement back cover for $8 + $3 shipping from Amazon. After 4-5 full cycle charges, it's giving me 2 full days of life after HEAVY use. The back cover is perfect and makes the phone much easier to use (for me anyway). Hey, for $8 who cares if it doesn't last forever? Amazon.com: HTC Evo 4G 3500mAh Extended Battery + Cover: Cell Phones & Accessories