Although a user's navigation history contains a lot of hidden information about the relationship between web pages and between users, this information is usually not exploited. The information hidden in the history can be an invaluable source of knowledge in assisting a user to better surf the Web. We present a system which actively monitors and tracks a user's navigation. Once a user's navigation history is captured, we apply data mining techniques to discover the hidden knowledge contained in the history. The knowledge is then used to suggest potentially interesting web pages to users.