I’ve added RSS feeds for all shelves, yours or others’. The link to the feed is on each shelf’s page, attached to one of those ubiquitous (and now even more ubiquitous) little orange feed icons. These feeds will contain all the items currently on the shelf, and will let you know if they were added or edited. Eventually I’ll include deleted items, but right now I actually delete them so all trace is gone. I’ll make deletion lazy at some point, so that there’s evidence that you used to have an item on a given shelf.
I tested the RSS feeds with Google Reader, Bloglines, Safari and Firefox. Let me know if you find a problem using the feed.
In lesser news, the default page size for a shelf is now 100 items, and whatever page size you choose is saved, but only for your own shelves. I plan to introduce saved preferences for viewing other folks’ shelves too, eventually. There are two reasons for the bump in page size. First, I managed to speed the site up by finding some data I can cache instead of hitting the database as much, and so the perceived load time for pages has gone down, allowing me to show the entirety of a normal-sized shelf all at once. Second, the page metaphor is really an old-school optimization for sites like Amazon, and it was by playing with their web services that I got into that bad habit — they have a model of 10 items, one page at a time. It was using their web services that got SC.com started, and so it’s natural that at first I matched the shelf metaphor to their concepts, but dammit if I’m not breaking free!