This morning Google Reader quietly added a new feature: search. Given that Google is best known as a search engine, this kind of functionality may be long overdue, but its utility makes it a welcome addition.

The search box, which appears at the top of any page within Reader, allows users to search for items within their subscriptions. A search can be performed on all items or just across individual tags or subscriptions. Search functionality is, however, limited to a user's own subscriptions (including any shared content to which you subscribe). To search all blog content, users will still need to use Google's separate Blog Search tool.

From a usability standpoint, search results are a breeze. Note the green border that appears around the results, making it instantly clear to users that they are viewing search results, not regular subscription content.

Google also made another welcome change to Reader today. Unread counts now go to 1000, so no more folders and subscriptions displaying a less than helpful count of "100+."