This is probably best as a feature or widget rather than a product in its own right, but wouldn’t it be useful to be able to easily search a blog or other website for all posts or pages that you had previously viewed - sortable perhaps by viewed date?

I have just spent almost half an hour trying to locate a post that I read on Guy Kawasaki’s blog about a month ago. I couldn’t remember the specific contents on the post, except that it was something to do with presentation and had sparked an idea in my mind. Just try searching on Guy’s blog for the word presentation. I went through what felt like hundreds of search results pages, occasionally seeing a dimmed hyperlink indicating that I had read the post.

I eventually found the post but it would have helped if I could have just requested - show me all posts containing the word presentation that I have viewed on this blog, sorted/filtered by date.

I wonder why a service like MyBlogLog doesn’t provide this - or do they? They could potentially implement in such a way that only the reader has access to this ‘history’ information unless she chooses to share it with her ‘friends’.