From their site: My Web is a personal search engine from Yahoo! Search which enables you to save web pages (including full-text cached copies), share them, add notes to them, and use the power of Yahoo! Search to re-find them instantly. My Web comes in two versions. My Web 1.0 allows you to store URLs in folders and share them with other users. My Web 2.0 enables you to tag URLs and share those tags publicly if you choose. Each version is independent and has its own data and web services.