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On your Recent Activity page (always accessible through the user dropdown menu), you'll notice a new little widget giving you a link to an RSS feed for your personal activity.
There is a bit less in the RSS feed than is available on the Recent Activity page when logged in. The RSS feed is nearly the same as "Social Activity" from "Other People." On the Recent Activity page, there is some private information like when you log in and out and make Pens private or un-private. We do not expose anything like that in the feed.
We originally built the feed to have everything and a fancy user-changeable security-by-obscurity URL, but we scrapped that because, frankly, it was kinda boring to see a RSS entry of yourself logging into a website. Keeping up with social activity this way though is pretty nice. Here's some simple examples of my own feed in Feedly, my new reader of choice:
This is just another step toward having good fleshed out feeds for all areas of the site. We have plans for many more, and the pieces are starting to fall into place for them. Happy to hear your ideas as well!