New Zealand director Grant Lahood created a short film (12 minutes) called Lemming Aid that won the Jury Prize at the Cannes Film Festival in 1994. You can order it from TVNZ Enterprises as part of a video compilation of comedy short takes. Film.com's "New
Directors New Films" page describes it as "A group of lemming watchers take the dive. . ." Does anyone know more about this film?
And last but not least, the most common lemmings on the internet are those fictional green-haired critters from the Lemmings game. Check out the Lemmings Games Web Page