From Bitsmith Software:
Take control of your notes with Personal Knowbase. Capture your thoughts and clear your head. This freeform note management software is easy to use and yet can handle a large amount of information. Simply type, copy, or drag your information into the software, give it a few relevant keywords, and rest assured that you can access it when you need it. Attach images and other files to your notes to organize all your information with the same set of keywords. Use it like digital index cards to manage your clippings, ideas, plans, contacts, archives, research notes, and references.
Features: Import many files types. Link to web sites, e-mail addresses, and files. Cross-link notes. Protect privacy with passwords. Bookmark important notes for instant access. Combine keywords in queries using AND, OR, and NOT. Set reminders on notes. Run from a portable USB drive. No limit to the size of the database or length of the notes.