If you've rooted your HTC EVO, but you haven't taken the time install a ROM that has tethering included – or you haven't unlocked the hotspot app yourself – then listen up: WiFi Tether for Root Users is back in the Google Play Store right now, although it's unclear how long it will last there. (In case you forgot, Sprint recently followed AT&T and Verizon's lead by removing all "illegal" tethering apps from Google Play - formerly the Android Market – last October.)
I should note that this is currently the beta version of the app, but that is fine; I've installed it and tested it myself, and it works flawlessly. The stable version still is blocked by Sprint, along with PDAnet, the paid version of EasyTether, and a few others. It seems like there are a couple miscellaneous tethering apps that haven't been blocked yet, but WiFi Tether is by far the best, and the most stable.
Since there's no telling how long this will last before Sprint catches on, go ahead and download it now. Of course, if it does get blocked, you can easily sideload it from here, but who wants to do that when Google Play makes it so easy?
Download: Google Play