1st - you need to uninstal htc sync and htc drivers
2nd - download unrevoked 3 from
http://www.unrevoked.com/recovery/
3rd - run the Reflash-bundle.exe you downloaded (it will ask you to extract to a folder) I created one called unrevoked3. it will extract all teh files you need
4th - plug your phone in and run reflash.exe from the files you extracted.
5th - follow the instructions in the popup window and it will root your phone enough to install the tethering app
6th - use the attached file and save it to your sd card.
7th - install the tether app you just downloaded
8th - when prompted select remember for superuser access
9th - you can start wifi tethering
i will be happy to answer questions about the setting up of tethering but not on how unrevoked works.
hope this helps if you havent updated to the OTA 1.47 you can still use the old unrevoked way in my signature
*********** wireless_tether_2_0_5-pre3.apk and wireless_tether_2_0_5-pre4.apk are experimental ***********