Social Media Integration?

Here’s something I’d like to see: a plugin for my browser that integrates with my various site subscriptions to let me know when I view a page that I already have linked or bookmarked from a service like It would have to store cookies locally and sync via iDisk. Because if you’re anything like me you work off a minimum of 2 machines, and often 3 or 4. I don’t know how many times I have come across a site that looks familiar, but I’m not sure if I’ve seen it before or not! -kenny