You can!
To find out the age of an object, right-click it, Edit > More > More > Inspect.
Watch as it digs up the creation date — it'll examine all prims in a linkset, making it useful to see when there's multiple creators involved. Thanx to Cube Linden for this feature!
(Yeah, it's buried 3 layers deep, and is part of a larger "first-use metadata" project, so like so many other things Second Life, it's subject to change.)
Let me know if you find anything older than this, it's "The Man" statue @ Philip's Hill in Natoma.
Dear Torley.. I was about to say "omg I can't believe after all my wanderings, I haven't seen this function before" argh.. but are you pointing out a new feature? It *definitely* gets my vote for a feature to hang on to!
ps. I do like your addition at the top of the statue!
Cheers
Some parts of Governor Linden's Mansion are just a few days older than The Man. See it here: [link].
(hope that shows up)
@Daedalus: GOOD FIND! Wowee, never knew that before.
@Simondo: It's pretty new and planned to be expanded to be more obvious, and documented. Thanx.
[Totallyofftopic]Why Torley what is that robotic watermelon-ii avatar ye have there? Doesn't look like the prim one I saw… hmm
@Nyalee: Same robot ("SLoundwave") av I had before, mebbe different angle?