D-ro Read has written a nice followup on the LAN party. I thing he's exactly right. For many things, discussion on the Internet(s) will work fine, but at some point, you can be a lot more productive when you have everyone face to face. The work on the webpages was critical, but there were several other things that took place that are probably equally important.
Getting everyone up-to-speed and on-the-same-page is a lot easier face-to-face. As everyone worked, we could listen and one person would explain to another what we were doing, or how something worked, and join in if what that person was saying was different than what we thought. This back-channel communication was really valuable for achieving concensus on building the site. We also could easily change modes, from "work" to "discuss" to "play". This leads to my next point.
Bringing everyone together creates a stronger peer-bond. Most of us knew one another from before, but working and playing together helps cement personal relationships. Having us jostling one another and grunting like children while getting into the car seems trivial, but those kinds of experiences can help tie the group together and build trust.
Finally, having a few relaxation periods: watching Blade III and looking for the Esperanto references, taking a stroll in the park, acting out good-armadillo/bad-armadillo, created a pleasant atmosphere and gave us a variety of opportunities to reflect on what we were doing and why. It's a great model for getting stuff done, which I think we should all consider doing more often.