In Bizarro World, Mike Mongo may be my doppelganger. The evidence:

⋅ Our names both start with the letter M.
⋅ I'm a limeonaire. He claims to be a humannaire.
⋅ I own epigrammatic.org. He owns (but hasn't yet used) ecopathic.com.
⋅ I'm on MetaFilter. He's on MetaFilter.