Landmark Forum?!

Does anyone know any insider info about a 3 day seminar called Landmark Forum? There’s someone at work who went to one recently and came back ranting about how wonderful it was, wanting all of us to go as well. It sounds like an intense 3 day (9am-midnight) intro to zen kind of a thing. It also sounds a little fishy.
I haven’t been able to find any info on the web debunking it’s legitimacy but I’m still looking. Any info folks?

It’s basically a self-help/group awareness borderline cult similar to est.

Here’s a skeptic’s opinion:
http://skepdic.com/landmark.html