Well, MovableType is working very well for me. One reason is that you can have multiple blogs on the same server. I've set up a couple more that are project specific. Now the challenge will be to see if the other participants begin to use this. Worst case I can envision that I'll be copy-pasting their email into posts. Best case is that we all share and as new participants join the project we'll point them there for the project history.

...stay tooned.