Unlocked phones

So I'm a little unclear on the whole unlocked phone thing. If I buy an unlocked phone -- say, for example, the GSM version of the Storm, a Nokia N96, or any other unlocked phone -- does this mean I can simply pop in my existing ATT SIM card and all the features of the phone will work? Do I have to go through any sort of setup or pay an activation fee with the carrier, or do they even need to be contacted? And this is all legit, right? They're not going to cut me off when they discover the phone on their network?

As far as I know (and my Blackberry is Unlocked - did it myself) it doesn't matter what phone you use on what network as long as the SIM is registered to the Carrier.

Data charges and the like may apply, however.

Exactly!! Using unlocked devices on your carrier (or unlocking your device for use on another carrier) is perfectly legit and legal ;)

Your carrier should even provide you with an unlock code for your device if you are in "good standing" with them (bills paid, etc etc).

In most cases all features of unlocked devices will work if supported by the carrier you are using the device on. For example, unlocking the Bold and using it on TMo will result in the 3G not working...

Things like that can occur with any device if the functionality is not supported on the carrier you are using. But, getting an unlocked 9500 from Rogers and using it on ATT should work fine :)