Found it on another forum! A third-party app bundle called "iChat bundle for iSight" on
www.ecamm.com. Just purchased it this morning ($21). Very pleased with what I've seen so far. Aside from being able to record your iChat video conferences, it also includes video effects (app called "iGlasses"), and a multi-conferencing app called "Powerboost" that I don't yet quite understand. I was hoping to find a free app, but this is reasonable, and rather worth its price.