Recently Google added the possibility to share items in their RSS-based Google Reader. The items starred or labeled can be shared with friends or other readers, creating a feed to which others can the subscribe via any RSS-reader. There is a link Share now next to Edit subscriptions, where you can share either all starred items or just the ones using a certain label. You can also create a clip, an HTML code snippet for your webpage that shows the headlines and links of your latest starred or labeled items.
Sharing what you read via RSS will be an important feature in the future. This means more and more feed readers will need to work on the server side of their solutions. It is easier to do this in web-pages readers and probably harder in Windows-based clients, many of which do not have much intelligence on central servers. It will be interesting how other readers act to this or what they add.
In a way this is del.icio.us or social bookmarking for RSS reading. Way cool in my opinion. It shows the strength of Google also in many other fields in the future, where you share more and more of the stuff you do or how you act.