You can also inject "naked" comments into your shared item stream, and you can use the "Note in Reader" bookmarklet to create a Reader stream note on any web page. It's microbloggy-twitter-statusy-social-graph stuff.
I've been using this stuff on the standard and mobile web clients [1] for months, and it works for me. I don't have much use for Twitter, but I use my Reader Notes as a way to track ideas that might turn into blog posts, and to create an annotated repository of things I find noteworthy. That repository is searchable in Google Reader.
These notes are shared as well, but Google tells me no more than 2-3 people are following my Shared items (My wife reads them too, but as an embedded feed rather than via Reader. She's my favorite reader by far).
Whereas I'm not well "followed" (sniff) I truly enjoy reading the items shared by those I do follow, such as Jacob Reider, Thomas, Rahul, Jesse Stay and John Munro [1]. Their crowd-sourced items and notes have significantly broadened and improved the quality of my knowledge stream.
Reader gets more love than most Google products, but there are still issues. Here's a quick summary of stuff to watch out for ...
- Features are scattered and surprising. In writing this, for example, I found a "Comment View" that shows comments on my posts -- I didn't know there was a way to see these. Sorry Rahul, I've just now appreciated your comments!
- There's a strange intersection between Google Contacts "Groups" and the ability to "Comment" on a shared item. I don't know if it's necessary, but I added the people I "follow" to a Google Contacts Group I created called "readers".
- When I read a shared item with a Note, I want to reshare it with a Comment. However if I add a Comment it doesn't show up in my Shared or Notes view or my shared item feed. Comments are an awkward design fit.
- I sometimes Star items that I also Share w/ or w/o a Note. Sometimes the Starred Item shows the Note and the Noted item shows a Star, but sometimes I get separate Starred and Noted items.
- The Mobile version of Google Reader is due for an update. It's missing several of the key features of the standard version such as "Like" and "Tweet".
- If I read an item, I don't want to see it again. Sometimes this works, but if several of the people I follow share an item I may see it 4-5 times.
- Gordon's Tech: More of me: My Google Reader Shared Item Feed
- Google's confusing social graph strategy: Google reader friends via Google Chat
- Gordon's Tech: Google reader shared items to Facebook
- Gordon's Tech: Google Reader: Feed Bundles and Shared Items