When I ran a guild with the DKP system, I stored it in a google doc sheet that everyone in the guild could view. It's pretty ugly, but it did it's job fine. Other than that, all I want to say about (non-retarded) DKP systems in general is that they are very good if you want to reward activity, but notably lacking if you want to reward performance.
This was how it looked:
https://docs.google.com/spreadsheets/d/ ... edit#gid=0I used WebDKP (an addon) to store the DKP from one raid ingame and then I simply transferred that into the sheet. I doubt my solution was anywhere near optimal, but it was nice to have all of the dkp so visible for everyone in the guild.