@Jonathon, probably wasn't being clear. I could set up a Pipe where I poll each comment feed directly, combine them, and then filter for me as author. But this requres editing the pipe each time I want to add a new blog. Using Google Reader as you say makes this a two click operation (subscribe, then add tag).

I will look through the other suggestions when I have a chance and see what the options are. Of course if we had semantic search (with link to RSS feed) this wouldn't be a problem.