Being somewhere between a "Newby" and an "Old Timer" I know that Groundspeak no longer allows new Virtual caches. You can still find the existing ones but no new ones can be placed.
Makes me wonder about Locationless (Reverse) Caches. Looks like those ended at the end of 2005 or so. I know a lot of you have found these caches before. Can you tell a little about them? Did you have a favorite Reverse Cache? Did you ever place one?