If you have a Sprint EVO 4G and have updated to Froyo, then you've been robbed. What's bad about that is you may not even realize it yet. The thief was none other than the manufacturer of the phone you so dearly love. Talk about betrayal! HTC, for purposes of forcing customers to use their Sense UI and it's components, didn't quite give you the whole package when it comes to Froyo. Fortunately, some knowledgeable people out in Internet-land have stepped up to restore our lost apps. First up is the stock Froyo 3D photo gallery.
The default gallery app that comes with HTC Sense is functional. It does what it's supposed to do, albeit in a very sterile and mundane fashion. However, this isn't what Google had in mind for a gallery app. When it comes to eye-candy and the all important coolness factor, the HTC app comes up lacking.
Fortunately, you're not stuck with mediocrity. Thanks to user ivan over at the HTCdev.net forums, you can now grab the original stock gallery app (aka cooliris) that was meant to go with Froyo. When it comes to dressing up in a slick UI, cooliris shines. All of your standard features are there for viewing your images, but it's presented in a much more interesting format.
If you're interested in downloading the app, you'll need to create a user account at the HTCdev.net forums (don't worry, it's free), and then download the APK file from the post I've linked to below. To install, you'll need to copy the file to your phone via the method of your choice (i.e. Dropbox, mounting your SD card via your PC, SwiFTP, etc.). Then from your phone, just browse to where you copied the file (via a file manager such as ASTRO) and open it.
Here's a few screenshots for your viewing enjoyment.