Project-Based Learning in the World Language Classroom

Thanks to my PLP network, I've received some great resources lately for project-based learning. Unfortunately, I still haven't found what I'm looking for - good research and/or guidelines for using PBL in the world/foreign language classroom.

Here's my problem - in the language classroom, we're focused on 2nd language acquisition. It's like building blocks. Yes, there are skills the students have to learn/practice. But there are certain amounts of content (vocabulary, syntax) without which they can't "build." So I can't figure out how to do PBL effectively without sacrificing what I think is important. And I would love some help!

I was inspired yesterday when I discovered that a post I made on a discussion forum (on this topic) was tweeted out - not by me. I assume it was tweeted by the discussion moderator. So I figure the wider I cast the net, the better the catch. So if anybody out there knows where I can look, will you let me know? I know they're doing great things in 2nd language acquisition in Scotland and Australia. Anybody over there using PBL effectively in a language classroom? I'd love to learn from you.

Thanks in advance!