The Gathering (Also known as TG)is supposedly the worlds largest LAN.
It is arranged in Norway every easter, usually in Vikingskipet in Hamar.
The Gathering 2002 had approximately 5000 attendees.
With compos in the areas of graphics, games, usual demoscene
stuff and weird compos it is a pretty entertaining party,
if it wasn't for the domination of gamers.
It is recommended to rent a hotel room, if you do not wish to sleep on hard concrete floors and makeshift beds made from chairs.
For a better and more informative node about The Gathering, see TG
http://www.gathering.org/