If you're rocking a T-Mobile US HTC Wildfire S, you were probably disappointed when you found out that HTC didn't include supported firmware to unlock the bootloader on this particular model with their recent round of updates -- I know I was. Turns out it was a pretty easy fix, and with a bit of trickery you can use the official tool to unlock the bootloader, then have a bit of fun hacking the extremely pocketable Wildfire S. After the procedure, you're pretty much off the standard update path so be sure this is what you want -- there's no turning back. That being said, everything seems to be working just like it was before I unlocked it, including Wifi calling and 3G. If you love your lil' Wildfire S but can't stand the limited application space, have a look at the link.
Source: Android Central forums