Site which archives most content annually? How-to?

I would just create a menu link to the node for that event, which is under the Annual Events link. That would be a link to the current year's event. It requires modifying the menu in admin manually, but is pretty easy.

Here's another way that this has been done: The Drupal Association's Drupal Conference web site spins each bi-annual event to its own sub-domain with the upcoming event and recent event's site on the main domain. However each site is separate and doesn't link to older sites (hmm...).

I'd probably just do it the first way.

I'm in a similar situation, and what I've done so far is:

• Archive the old site with http://www.httrack.com/
• Unpublish all the old event-specific content

This works more or less OK, but has some drawbacks:

• A bit of manual work for each new event
• All links to the old event are broken
• HTTrack gives pretty ugly URLs, and there's a problem with encoding of special characters which I haven't figured out yet

I've started to use taxonomy to categorize the content that's specific to one event, and I'm using http://drupal.org/project/taxonomy_defaults to ensure that all content created is tagged with the next event.
I'm thinking about:

• Using pathauto to give all content a path starting with the specific event
• Using Views to split up taxonomy views per event (so clicking on the tag "boardgames", I'd get board games for just this year's events, and perhaps the earlier ones on tabs or something)
• Maybe look for a module for taxonomy dependent theming, so there's a clear visual difference between this year's events and earlier ones

Since this is a project I do in my spare time, I don't know when/if I'll ever get around to doing it. I'd be interested in hearing what you decide to do.