If you have past the activation screen on your phone you can go to Settings ---> General ---> About:
Scroll down till you see 'Version'.
If you are are still at the 'Please connect to iTunes' screen and cant do anything with the phone try this:
Slide into emergency mode: type *3001#12345#* then tap call. You will get a new menu. Select Versions. If your phone says you have 03.14 your firmware is 1.0.2 if it says 04.xx then you have 1.1.1.
If you haven't already purchased a license please Click here to start.