They're not really a startup since they only accept donations, but I loved the idea so much I made my own version which does not randomly assign a string but instead allows users to pick their own phrase: http://www.oneryng.com
Maybe I should make that more clear...
Detecting circular assignments is a great idea though, thanks!
I wish you luck, but I can't help thinking rickrolling, goatseing, and spamming other people's links will be a problem.
Nice work on oneryng.. At least reveal the meaning of life though if you know it..