Interesting idea. Some quick questions:
- How much data do you store per user?
- How do I delete certain results? (preferably after the search comes back)
- Another thing to consider is - After how much time does this just become as painful as finding that page through a search engine?
- What version of the page gets stored? The latest or the one that I saw?
I guess its one step better than Evernoting a page and adding tags myself.
Good luck!