I have a unactivated iphone, but can not connect to itune because it keeps asking me to insert a valid sim card. Please suggest how to activated it so that I could download music and video into it. Thanks

I had the same problem. I bought a Rogers iPhone and I did not (and I still do not have) any SIM card.

What I did was to jailbreak it with the latest QuickPwn. It activated and jailbreaked my iPhone and I can now use it with no problem at all except for the *phone part.