How to use my iPhone 4 without a sim card?

I get my sim card for it Tomorow, but it won't activate without a sim card. Is there anyway I can go on it and when I get my sim card it will still work?

Added (1). But it won't even activate

You might be able to play with some of its functions but without a SIM card it has no phone number and it has no phone network access for calls or data. You should be able to use its Wi-Fi to access the internet though.

You need an active sim card to activate it. Warning: it is very likely that it will lock to the first network sim you put in it, so don't be tempted to use an old sim to activate it unless it is the same network.