I have 3 x 5 index cards and file them by user name in alpha order and on the card, I write down
user name (from where)
real name and address
birthday
comments: (like how long quilting, favorite colors etc.) and if I do a swap will have that information on it
also has a calendar to put down when swaps are due, birthday list etc. (and can set up a reminder for yourself)
also you could create a private yahoo group to store the information online with databases for swaps, address book and you can store your links there from surfing etc.
I have one! for my eyes only (private)