MGL joins the aging fray with a 20 page PDF. He tries many different methods, including correcting for survivor bias by using "phantom" seasons. If you just want the punch line, he comes down on the peak age at 27-28 side.
Tim Dierkes has a list of the most interesting non-tenders. I was entirely unaware that anyone called Mike MacDougal "Mac the Ninth," but I find it very amusing. (Thanks to Jesse Spector.)
The love letters to non-tendered players are streaming in. Here's R.J. on Gabe Gross, WHYGAVS on Matt Capps, McCovey Chronicles on Ryan Garko, and Lookout Landing on Ryan Langerhans. Just read the last paragraph of Jeff's Langerhans post.
Russell's paradox as applied to the speed of Rickey Henderson. We can be certain that no one steals more bases than Rickey.