From Homestar Runner Wiki
All you wanted to know about PlasticDiverGuy:
Real Name: Mark Annis
Location: Dartmouth, Nova Scotia, Canada.
Employed currently as a bus driver for Metro Transit in Halifax. At the time of Sbemail171, I was a team leader at a call centre and I actually did have to talk to someone because of a complaint I got about an underling's stench. I wrote that email that night at 4am after speaking with the employee. I was alerted via a random person on Facebook that my email was used.
Discovered H*R in 2002. I watched week after week as the weekly SBEmail would be posted on Fark.com. Eventually, my curiousity got the better of me and I clicked the link. The email was guitar and I've been hooked ever since.
Submitted email #171, underlings
Also uses handle on the following sites:
YouTube, MSN Gaming Zone, Fark.com (the first place I used it back in 2004), Arelith forums and on the Arelith NWN server, WAYN.com (signed up years ago, then abondoned it. Came up in google search for PlasticDiverGuy)
Plastic Diver Guy gave out clues on PBS' Where in the World is Carmen Sandiego?. He had a catchy theme song, performed by Rockapella, "He lives a life of danger! Our underwater ranger! The one and only Plastic Diver Guy!" He'd then give the clue. At the end, some horrible fate would befall our little plastic man when the ominous "Oh no!" music came in, like a shoe falling on him. I picked him as a handle because noone else did, and I could easily (though with blank looks) explain its source.
Fun Fact: I own the T-shirt my email spawned and wore it to work on more than one occasion. Gotta love tact and professionalism.