The idea is simple and childish:

1. Watch twitter's public timeline for any directed tweet that says "That's what she said" or equivalent.
2. Put the original message on thatswh.at.
3. Profit.

thatswh.at is made possible through the generosity of Google and their wonderful App Engine. And of course a special thanks goes out to Twitter.

Enjoy and let me know if you have any questions/concerns.