Just to be clear:
I designed this feed to be used with my favorites on blo.gs. Blo.gs uses, among other formats, the RSS format to share favorites. I chose RSS for this plugin because it is a major standard as well as because this enabled me to use the cache functions of the LastRSS library.
The blo.gs RSS feed I am referring to lists each favorite as an item in the RSS feed. The title element lists the blog title, the link element lists the blog's URI, and the pubDate element lists the blog's last update as reported to blo.gs.
My plugin reads this feed, grabs the pubDate elements from each of the items, and inserts those times into the update time field of the wp_links table where the URIs match. It does this every time the page loads, unless the cache is enabled, in which case it does it the next time that the page loads after the cache has expired (usually after an hour).
WordPress' own update-links file does largely the same thing, but with the Ping-o-matic update service, which tracks far fewer blogs. It also lacks a cache function, because it is designed to be run as a cron job at regular intervals in Unix.
This plugin should work for any RSS feed that takes the format I have outlined above. However, I designed it to be used for blo.gs favorites because that was the service I knew of that tracked most blogs, that allowed public sharing of favorites, and that would allow me to use RSS.
I hope this helps.