Aviation Auction
Found this site from another (much more obscure) discussion board, and thought it might be worthwhile highlighting here for the numbers of wanted/for sale posts that appear before they get moderated out of existence:
Only seems to have gone live a couple of weeks ago and looks like a pretty professional setup, although seems to be currently concentrating on aviation memorobilia.
Discalimer - I'm in no way affiliated with this site, and since it's a free service with an aviation slant I hope this isn't considered advertising!
In itself the site is not advertising as such, but there are a good few commercial organisations shown there who are, and that we cannot allow it.
PPP