just got an new "virgin" iPhone
used idependence to find out the firmware version is 1.0

now I need to know the pros and cons for upgrading the firmware.
or leaving it and unlocking etc for antoher carrier

I'd like to unlock the phone to use on another carrier but also have as many features as possible working on the phone.

So what are the pros and cons of just diong this from fw 1.0
or upgrading it to the 1.1.1 and then trying to get it onto another carrier?

I've read that some anySim type applications can limit my options after the fact

any help would be great thanks