Wanted: pointers to baseball aging studies

Next week, at the American Statistical Association convention in Denver, there will be a sabermetrics-related session. It's called "What Can Statistical Methods Tell Us About Steroid Use and Its Effects Among Major League Baseball Players?", and it's partly in response to some of the analyses of Roger Clemens' career that have recently got some press.

I have been invited as a panelist, and will be giving a short presentation on what sabermetrics knows about aging in baseball. Most of what I know comes from Bill James' long essay at the back of the 1982 Abstract. I'm also aware of some of J.C. Bradbury's work over at his Sabernomics blog, and the recent JQAS article by Ray C. Fair.

Does anyone know of other studies? Any help would be appreciated.

P.S. In another session, there will be three papers presented on home-field advantage ... I'm not involved with those, but I'm looking forward to attending.