The most efficient way I could figure for doing this was to subscribe to Donation Coder in my Google Reader.
That way, the unread posts then all obligingly pop up for me to skim over or view as I see fit. If I spot one that I want to read, then I can either read it in Google Reader, or (maybe better) click on it and that takes me to the whole discussion thread in the DC discussion forum. (That's exactly what I did before I made this comment.)
I don't want to read all DC forum comments, and I use Google Reader to enable me to to quickly see which are the new unread comments for any given discussion and which are new discussion posts.