Rocks -- This is a common nickname for me. The pronunciation of my last name sounds like "Rock-olz" -- especially with how my family has kind of Americanized the pronunciation over the generations. A good German will say it with alot of throat clearing and whatnot.
MTU -- stands for Michigan Technological University. This is where I got my undergraduate degree. I also hope to retire up there some day (though that is still probably 25 years away). If I recall, when I signed up for the site, just "Rocks" wasn't available, so I threw the MTU at the front.