Just in case this saves anyone else some stress. I just rooted my stock OTA 2.2 Desire using Unrevoked 3 on a Mac. On my first attempt I literally plugged in and pressed OK: the process involved many reboots, much waiting around, and if a boot went as far as asking for my SIM PIN I entered it. At the end of which it said "Waiting for root... (safe to restart if this doesn't work)". After a while my phone came up with a "force close" or "wait" message for "system". Thinking it might be safer to wait, I selected the latter. And waited.... After a long while of looking at a black screen and nothing changing I decided that restarting might be a good idea. And this is where it became stressful: the phone didn't respond to the power button, power + volume,... The only sign of life was that if I held the home button it told me that there were no recent apps (though that did stop me thinking "bricked"). Eventually I forced a restart by pressing power+volume down+trackpad button. Then when it came back Unrevoked informed me that it had failed to get root, and that "this sometimes happens. Restart and try again". Reassured by the fact that my phone was still alive (!), I did try again. Before doing so I disabled interactions that would normally follow a boot (WidgetLocker and SIM PIN), and following a hint on the Unrevoked webpage I put the phone into disk mode when I connected. This time was a completely different story: everything was fast, there seemed to be fewer boots, and a couple of minutes later the phone was up, running and rooted. The mac did complain after the first boot that I'd uncleanly ejected a disk , but that was to be expected. So, apologies for the long post. I don't know whether the initial worrying experience was connected with being in charge only mode for the initial connection, or the various locks and PINs getting in the way of something, or just plain bad luck. But no harm was done and the second attempt was very painless. So I just wanted to tell anyone else doing this not to panic even if things do seem to be going very badly wrong, and maybe to try the "connect in disk mode" suggestion if rooting from a mac.