Just got iPhone Gift card - already have ATT - I have to drive to Apple St?

I just got an iPhone 3G Gift card for the 16 gig version. ($299). I already have ATT service, for over 10 years. Currently have a Blackberry. But the instructions on the gift card concern me. I have an ATT retails store a mile from me (I can't go right now and ask, I'm at work). Do I actually have to drive 75 miles to the nearest Apple Retail store in order to get it and activate it? HUH? I can't go to my local ATT (company ATT store, not an agent store) and get my phone and set everything up? Sorry, but I do not trust the Apple Store to not muck up my ATT account, and how in the world would they have THAT much access to ATT's system anyway? I will NOT have that happen. Tell me this isn't true. LOTS of people live nowhere near an Apple Store. So..........????