You have two options.
1. When the iPhone is available for pre-order, do so from apple.com. Then just sit at home on release date and conveniently have it delivered to your front door.
2. When the iPhone is available for pre-order, make a reservation at your favorite Apple Store. Then show up early on the morning of release and get in line. Socialize with the other enthusiasts waiting for their iPhone, experience the "show" that the Apple employees put on at opening, possibly get interviewed by media, and buy your phone. Then set up shop at the Starbucks that is inevitably near the Apple Store and sync all your data. After playing with it for awhile, head home swearing to take a nap because you're so tired after getting up so early. But then when you get home, continue playing with iPhone until you finally pass out from excitement and exhaustion on your couch at about 11p.
You can probably tell which option I normally go for