My friend Rex Hammock writes about FeedDemon’s "Popular Topics":

"The FeedDemon feature is, in effect, a meme-tracker. However, instead of analyzing news stories and relevant blog posts that are being linked to by a mysterious universe of topical-bloggers (or folks trying to game it), the feature analyzes the stories that are being linked to by those in a network of bloggers you choose — those to whose RSS feeds you’ve subscribed…In other words, it’s like having a Techmeme that is “memetracking” topics important to just those bloggers you desire to follow, rather than all bloggers who post on the topic."

I have to say, it’s nice to see popular topics getting some attention.  The first time I showed this feature to anyone was at BloggerCon IV in 2006, and I remember Chris Pirillo being impressed by it.  Popular topics has been greatly improved since then, especially in the new FeedDemon 2.6 pre-release, but I’ve seen very few comments about it.

IMO, a "personal memetracker" like FeedDemon’s popular topics is a killer feature for aggregators.  It’s something we should expect in our RSS readers, because the more information we subscribe to, the more we need a feature that shows us what the people we’re paying attention to are paying attention to.  Dare Obasanjo considers it one of the top five features for the next version of RSS Bandit, and he nails why it’s important (emphasis mine):

"I’m now officially at the point where I don’t have enough time to read all the feeds I have in my subscription list anymore. For the most part, I’ve gotten around this by browsing programming.reddit, Techmeme and Sam Ruby’s MeMeme about once or twice a day. Although they are all great, the problem I have is that there are parts of the blogosphere that none of these sites is good at tracking. For example, none of these sites is really on top of the Microsoft employee blogosphere which I’m interested in for obvious reasons.  I’ve been talking about building a feature similar to FeedDemon’s popular topics for a long time but I’ve now gotten to the point where I don’t think I can get a lot of value out of my blog subscriptions without having this feature."

I’m willing to bet that over the next year or two we’ll see personal memetrackers appear in more desktop aggregators, and despite the computational and scaling problems, it wouldn’t surprise me if more web-based aggregators also offered this feature.