I really liked www.linkedin.com's semi-subtle approach. I didn't even notice at first, except that I got one of their legitimate emails saying an old colleague wanted to connect. Among the 'people you may know', I got:
Werner Heisenberg - physicist. this *may* have been his profile
Ernest Hemingway - Author
Sherlock Holmes - Detective
You get a different list every time. This was the first year I noticed.