HTC Desire advice?

On Sunday night I actually had a dream about buying the HTC Desire. On Monday morning, eating my breakfast, I heard an ominous clicking noise that told me my hard drive was about to die. Putting these together, and with BiCon on the way, I finally stopped resisting temptation and went and bought one.

So, those of you who already have them - any advice? What applications should I be installing? What games do I need? How do I play videos copied to the memory card? Anything else I should know?

Looking forward to seeing lots of you at BiCon!

Update: I would have thought this was obvious, but: since I've just bought the phone this isn't a thread for advocating which phone to buy. Just had to screen one comment that had no purpose but to say I should have bought a different one!