If you're a manual-reading sort of person and want to get a head start on digging into the HTC EVO 3D's 315-page user guide, then head on over to Sprint and download the 3.75MB PDF now.
You won't find out anything new, especially since Radio Shack already showed us how to turn 3D on and off, but while less informed folks are struggling to pop off the battery cover, looking for the microSD card slot, and figuring out how to rearrange the home screens in thumbnail view, you'll already be enjoying your new phone.
[EVO 3D user guide @ Sprint]
