Firefox: Mozilla Labs' Recall Monkey extension adds a new page to Firefox that searches your history by time range, by site and other advanced filters to help you actually find the page you're looking for.Chances are you only delve into your browser history when you want to revisit a page you've forgotten, but sometimes that page is harder to find than you expect. You probably visited a number of pages on the same subject and did multiple Google searches that muck up your history search results.
Recall Monkey helps you ignore the junk and find the important pages: you can filter your searches by date, give priority to certain sites, exclude certain sites (like Google) from your results, and even tell it to float pages you've bookmarked right to the top. It also searches as you type, à la Google Instant, so you can really dig through your history easily.
Recall Monkey is a free download, works wherever Firefox does.