Q:

How to root a HTC Desire running official Android 2.3?

I have an HTC Desire (Bravo, A8181, GSM) sold in Sweden. I updated it to Android 2.3 using the official release, which is as of 2011-12-29 available at HTCdev with instructions from here.
Now I want to root it. I did some googling and it seems like it isn't possible to root a Desire that has been updated to the official Android 2.3. I tried following this guide, but it failed at step 6 in How to: Root. When I attempted to run unrevoked, the progress text running root... was followed by the error message Error: failed to get root. Is your firmware too new?.
I also tried searching for a way to downgrade it to Android 2.2, with no luck.
How can I root this phone?

A:

In my searching I stumbled across Revolutionary. It looked good enough, so I downloaded it and ran it. It prompted me to plug my phone in, and then it pretty much did the rest on its own. The result was that a custom recovery system was set up, from which it is easy to install ROMs and the like to the phone.
The Revolutionary docs mentions a zip file you need to install in order to root the phone. In order to install the zip file, I first downloaded it to my phone's SD card. Revolutionary only sets up the mentioned recovery system, so the official HTC Android 2.3 was still intact and running on the phone. I used that to mount the SD card on my computer and copy the zip file, but I could just as well have done it using Revolutionary.
After placing the zip file on my SD card, I shut down the phone, then held the volume down button and pressed the power button. This results in starting the phone's bootloader, from where one can start the recovery system (Revolutionary in my case). This greeted me with a neat menu containing the entry install zip from sdcard. I selected this and navigated to the zip file I downloaded. When the installation was complete, I rebooted the phone into Android, and my app drawer now contained the Superuser app. Root complete!

