SigChanger

SigChanger is a freeware program that automatically changes your e-mail signature. The program changes, without bothering you, a textfile (or HTML file), which you can use for your signature.

You can alter the constant text in your signature, aswell as the file with quotes (or whatever kind of text).
During the installation of SigChanger, a textfile with 101 sayings is automatically installed, ready for use in your signatures.