QUOTE(ac98 @ Dec 11 2006, 02:36 PM)
Huge lenses (dun have to be too huge, about 8" long will do) have an advantage of creating a 'blockage' in front of ppl where their head will keep on knocking into it. My tactic is simple : Keep on 'tapping' their head with your metal lens and say 'Sorry'. It's very painful if you get 'tapped' a few times trust me! I experience it once before ... during the RO Concert at Mid Vallery last time I didn't actually tap the girl's head, I actually knocked her with my 70-200mm and she yelled! Didn't know metal L-lenses are so hard until that moment.
What she did? Simple. She blocked me, and when I said "Excuse me" she looked at me and didn't listen. Sorry-lor, I didn't knock you, you were swinging your head to the song and you knock me mah!
A long range telephoto with IS/VR will do you good. A 300mm will suffice

Ouch... that's painful
I'm afraid will be easily caught by security guard hehehe...
Security Guard (at gate) : What is that stick pointing out of your beg? Please open your beg.
Me : Errr... nothing, it is just a stick for protection. You know lah, nowaday so many snatcher.
Security Guard (at gate) : Please open your beg.
Me : *can't be help*
Security Guard (at gate) : Sir, I'm sorry we can't allow camera in this concert. We can't allow you in.
Me : What the... I already paid for the ticket!
Security Guard (at gate) : I'm sorry, sir!
Me : *take the lens and whack the guard* EAT THIS!!! !@#$%^&^%$#@!@#$%^
Joking only

don't be serious

(Come to think twice, I'm seriously wanted to knock the head in front of me, coz he kept on block me

, worse thing, he wasn't totally in for the concert. As I can see he is not enjoying at all)