I used to use OneNote pretty extensively for nearly everything. Recipes, course notes, thoughts while working on projects, lists of reminders, etc. The main problem with it was that if I wanted to search on something, I'd have to search X number of OneNote notebooks.

I've recently started to use fedwiki instead of OneNote, and things are alrightish. Fedwiki has lots of room for improvement as a wiki, and then as a knowledge store.

I think the ideal personal information/knowledge store would incorporate a tagging filesystem combined with something like OneNote/fedwiki. The tagging filesystem would allow PDFs, movies, etc to show up in searches with fedwiki/OneNote handling the plain text & images. Ideally the client that the user uses is something like fedwiki, where you can have multiple different pages open at once, but also allow you to pull in the PDF/video resources.