I've always kept my study notes in neatly organised Microsoft Word documents. Now I'm finding that I have to remember, store and organise so much information that Microsoft Word just isn't doing the job, not to mention my memory.
I realised this was a pretty serious issue and I decided I would try and search for a "Personal Wiki". Turns out, personal wikis, PIM (Personal Information Management) and PKM (Personal Knowledge Management) are quite a hot topic. Some go as far as calling these applications memory extensions.
There really are heaps to choose from, but none of them really looked stable and portable enough for me. I need to be able to file, categorise, tag, save, backup, convert to HTML and print everything I document.
In the end I decided to go with Microsoft OneNote 2007. Not because it's a Microsoft software package, but because it does everything I need it to do.