in response to space monkeys problem, the same thing happened to me a couple of days ago , I've only had the phone a week! so was really disappointed when it went wrong so soon......
I got as far as the android fella waving too , then it just kept switching on & off , on & off like it was possessed!! the start up tone was doing my head in!!!
only way could stop it was taking battery off.... It would only stay on if i took out my sim card!...
anyway I took a kind persons advice (jaffa from the forum) and reset the phone & so far, so good... that was 2 days ago...hope i havent spoken too soon now