Hmm! Simple Modal - http://simplemodal.plasm.it/ may be just what I've been looking for, for my project, as I've moved from Prototype to jQuery, but still have to keep to Prototype hooks around, to utilize Modal Box - http://okonet.ru/projects/modalbox/index.html - I like the OS X-like styling of the, "sheet" coming down from the top of the menu, and ability to load via Ajax.

Looks like I may be able to hack the same sort of styling into Simple Modal, and it's got load-via-ajax already built in. (any other options?)