Windows only: Desktop Google Reader is an easy-to-navigate RSS reader that integrates your Google Reader feeds to other online services. With one click, send a story to your Twitter, Instapaper or Read It Later.
Desktop Google Reader provides integration with your Google Reader account and lets you share online to other services, complete with RSS notifications. It's possible to share a story through Twitter, through email, or send it to bookmarking sites like Read It Later. It also works with bookmarking service Instapaper. (You'll just need to make sure your details are in settings to take advantage of these features.) The interface is simple and straightforward, with keyboard navigation.
Unfortunately, there's no way to organise various feeds. Feed items are only displayable and sorted by web site. Hopefully, they add different ways to display feeds, such as sorting all items by reverse chronological order, in a future release. Desktop Google Reader is freeware for Windows only.