Getting oneself organized is a big hazzle and I have always envied this people who handle Filofaxes, mountains of paper and computer files with ease. I know there are CVS and all that stuff you can use for tasks beyond programming but I still have files like "paper.draft" "paper. new", "paper.best", "paper.endversion", "paper.done" etc. pp.
A Nightmare!!!

Fortunately, there is one place I am organized: Perl.
Thanks to Perl I was educated to have a ":lib" and a "site_perl". Exploring the ":lib" and CPAN helped me to get much more organized and to get a feeling for classification.
I throw away a lot of Programms I wrote for "one-time" use and usually I do not regret it. These little Data Munging programms are faster written than remembered as already (partly) written.
On the other hand, If I write a function I know I have to use again, or find a nice little function here on perlmonks, in books, newsgroups etc. I will more or less copy and paste it into one of my categorized "Hanamaki::" moduls. Of course some bigger scripts will become modules on their own.

Hanamaki