Mike- I agree that having an easier way to drop grades in for forum/collaboration work and participation would be a bonus. I currently create an offline assignment and mark it as "homework" and then review each forum and search by student. It is not THAT time consuming, but I do recall that WebCT had a process where you could pick up the # of posts.
My grading is simple- I assign one point per forum and if the students posts their original response AND replies to the posts of at least two others, the full point is earned. If the student neglects to post at all, but replies to others..I award .5 point- similarly, if they post their own but don't reply to others, I award .5. I try to be clear from the beginning about the expectation to post the first response by the week's mid point to avoid cramming responses in the last day. It's worked to be clear and then grade the forum immediately after it concludes so that students see that their contributions are measured and valued.