blo.gs: for sale. My own project BlogTracker was a precursor to blo.gs, and I mostly abandoned my version because I didn't have the time to make it work well. Part of my justification for abandoning it was that blo.gs seemed to be working nicely, and was filling the niche well enough for both of us. (BlogRolling also solved a similar problem in a slightly different way, and I'm told it works well enough for most people's purposes.)

RSS readers try to solve a completely different problem, and for many are a substitute for ping trackers in that they also surface new content in weblogs as it appears. It's a terrible solution for that particular problem, however, as it requires every reader's computer to hit the weblog directly every N minutes (however many the reader specifies, often a uselessly low number like 5 or 15). Weblogs.com's pinging solution was meant to prevent exactly this pattern of use, by allowing blogs to explicitly invite such programs to download new content. Nevertheless, RSS readers are popular, and ping aggregators thereby less so.

When Weblogs.com's service and reliability got spotty, blo.gs, which both used Weblogs.com's feed and gathered pings directly, became a nice secondary destination for blog pings. For a long while, Movable Type has included blo.gs in its default list of services to ping, so there's a large install base sending pings to the blo.gs domain name that's for sale. The obvious possibility would be that SixApart could pick up blo.gs and include the service in their suite of offerings, but these days I'm less inclined to assume small companies ought to be spending money to give me something for free.

There ought to be a competent, reliable, well-maintained, free weblog update ping aggregation and browsing service. If I could afford to host the service—or believed it could be sustained on donations—I would seriously consider making Jim an offer.