Randall Monroe, of xkcd fame, time travels four and a half years into the past to sign up for a MetaFilter account just so he can answer a recent question in Ask.
Dave Gorman pops in to comment in a thread about himself.
How do you picture the bona-fide MeFi celebrities? We read from them all the time, but they don't often give clues as to their real selves. If you don't make a meetup, you'll still need a picture of them in your head. So what do you think they're like? I'll leave the choice of celebrity up to you
Matt & MeFi (via Shift.com's list) named in SacBee article Are Internet celebrities the next big thing or simply one-hit wonders?