Hey - check this
out. My Desire is 5 days old. When I try to do what the guy says in the video (note that mine has an "applications" menu, not "programs") it doesn't work. Instead of killing HTC Sense, the program (Sense) comes back to life automatically. The screen goes white, then the HTC logo comes up, then it's business as usual.
I wonder if this indicates that my (new) Desire has something different about the software that is causing the atrocious battery life (mine is TERRIBLE!!). Perhaps HTC has changed something which has had detrimental effect?
Maybe people could test the technique in the video on their phones and see if we can find a correlation between phones that can do it and phones where the batteries 'work' - yes, I say work, because my phone is effectively useless if I walk 100m from powered USB ;-)