Thanks for the tip, Dynocoaster! This came up again (or a silver version of it) and I snagged one. There's one with a horizantal extention, also:
http://cgi.ebay.com/New-Alu-Folding-...item2a06eabb1f
I'm banking on that it clamps to a quill-to-Ahead style adapter (already got one of those).
Man I'm gonna miss that gentle rocking motion in my Mini's old stem!