Threaded Discussions

I think threaded discussions could be really useful in the fifth grade classroom! I have been really motivated to try these in my classroom. I have been thinking about how I could implement and use them.
I currently team teach with another 5th grade teacher. I teach 2 sections of math and 1 section of science each day. The students in our classes are ability grouped for Math and Reading. When we first decided to ability group, we were excited about being able to more closely tailor our lessons to the student needs. However, we were nervous that the kids in the lower level classes wouldn't hear as many good questions and insights. We were nervous they wouldn't be pushed to grow as much without these role models right in front of them. I think that if my students discussed their math lessons each day in a threaded discussion, these concerns could be alleviated. If I posted problems the kids could answer and explain their thinking, both groups could benefit. I would also be helping my team teacher get these kids writing more each day. It would be a win-win. I could also connect & extend the science units. Since the kids have science for 4 1/2 weeks, then social studies for the next 4 1/2, I'm often afraid they'll forget the information we've just covered. With the Science EOG being pushed this year I could use threaded discussions to keep topics close at hand while they are in S.S. I could post questions, real life problems and thoughts for the first group of students. They could respond at the time they are doing the unit. Then, when they are in S.S. they could have a discussion with the other class as they are learning. Or I could have them talk even if they hadn't had that particular unit as a way of spiraling the curriculum. I think it would be neat for them to see how they change their thoughts as they go on.
On those cold winter or rainy days that we can't go outside for recess, I think threaded discussions could be a fun & educational way for kids to keep in touch with friends in other classes, while squeezing in some more writing. Teachers could post a conversation starter, like "What would you do if your best friend wanted to join a gang?" or "What would you do with a million dollars?" Even if their friend didn't have recess at the same time, they could converse.
On my class webpage I'd like to have threaded discussions for parents. I'd like to have discussions on things like projects, field trips, etc. This could save me a lot of time that I currently spend on answering the same questions over and over again via email or phone calls.

I really think the possibilities are endless. I love the idea that I can easily incorporate more writing into my classes, in a way that the kids won't even realize they are practicing.
So, does anyone have any ideas for other ways I could incorporate threaded discussions into my science and math classes?