I just checked, and apparently explain.depesz.com is online for over a year now. First plans was added on 2008-12-04 13:20:43+01.
Since then there have been 3602 plans added, 770 of them were set to be private (not displayed on previous explains page.
Longest plan has 2267194 characters (yes, 2.2 megabytes of explain analyze output!), but it's not public, so I can't tell you the url. Longest public plan is this monstrosity, which (while being only explain output, not explain analyze) has 503585 characters.
During this time, there have been 61 days that nobody added any plan on (perhaps problems with software?).
The most heavily used day was 23rd of June 2009, when 71 new plans have been added (4 private).
Thank you all for using it. I hope you find it useful, and I promise, that one day, I will finally sit down, and add all long-due features (like work with new explain formats, fixing some output glitches, stats of used objects per plan).
If you'd like to take a peek at how it works – source of explain.depesz.com is always available.