I've just made the first release of a software project I've been working on -
ThoughtThing.
The basic concept is that my brain doesn't work in a hierarchical manner, while the file system on my computers (and pretty much everyone else's) insists that I organise my 'stuff' in that way.
In ThoughtThing, you build 'nodes' around yourself, and then define links between them in ways that make sense to
you. Each node can have unlimited parents or children, each of which is another node.
Each node can either be empty (a 'container' node), or have a URL tosomething - a website, a contact (as looked up in a vCard file), local pdf,whatever really.
In this way, you are free to build as complex a 'web', 'ThoughtThing' or 'TT' as you like, and link to whatever you find you need to organise.
If you want to try it out, you need a webserver, MySQL and PHP, and then to go and down load the code and let me know what you think :)