One such leak set out to enhance functionality on our beloved devices, is HTC's very own WiFi router app! This is one of those things, like USB mass storage mode, that should always have been in Windows Mobile but even though MS saw fit to let you use your phone as a modem via Bluetooth and USB, using your phone as a WiFi access point either involved a bit of hacking (in the old days) or more recently, by using something like the incredibly overpriced WMWiFiRouter ($29.99!).
Anyway, just like with USB mass storage mode, HTC has (eventually) come to the rescue with a very simple and easy to use app. Just had a little play on my HD and my laptop was seeing speeds of around 130KB/s with 2 bars of HSDPA (O2), which ain't bad at all! My only issue with this app is the lack of decent encryption - WEP can be cracked in a matter of seconds these days!
Check out the HTC CM WiFi Internet Sharing thread on XDA for more info.