When I was in line, much talk of Nintendo went on, including days of old. Good subjects to mention are Zelda (be sure to include the CD-i incarnations, they score extra nerd points!), NES follies (such as having to blow on the cartridge, or being able to shoot the Zapper gun at a lamp and still get points), obscure games (Diddy Kong Racing, Earthbound, Super Mario Sunshine, etc), and of course, the Virtual Boy.
Try you luck at branching off with references to recent comedy movies, events, and even internettings.
Honestly though, there will be long moments of silence, boredem, and so on. Go inside and buy a deck of cards, Taboo, Sorry, Monopoly... something to help pass the time.
If you are the girlfriend there for support, and have no clue of anything I just said... go inside, buy a paperback novel, read it, and when your boyfriend is buying the Wii, return the book. A parent did that at our camp-out... completely finished the novel.
Good luck!