What other internet forums are you a member of and what’re your user names?
I’m a member in quite a few sites so I’ll just list the ones I’m active in along with user names:
Alternate History Discussion Board User Name: General Mung Beans (Got banned created several sockpuppet accounts).
RevLeft User Name: Richard Nixon
Christian Forums User Name: General Mung Beans
nick: Socky <----got banned and then reallowed on the forum, but my original user name remained banned due to the original runner of the site leaving and keeping his power over the site, but not engaging with the site at all anymore. So teh mods who are still there allow me on, but the absentee landlord hasn’t given the all-clear for my old username, so I made the name ‘Socky’ for what has become my permanent sock-puppet account.
Pretty much just here and Ecunet. I’ll cruise Yuku for information now and then but pretty much as a deeplurk.
im a member of hipforums. its a clunky old site but i get a kick out of it
eGullet, for cooking stuff.
Here…alldeaf.com. Used to post at Hearing Exchange but the person whos an admin there is a NAZI…its also a sock for the CI companies and oral schools. Luckily its DEAD there!!!
I post at Help Kids Hear as voice of a formally hoh kid. As well as HLAA forums (somewhat active but mostly old people)
Only this one.
This one, Giraffe Boards, Tousando (a Japanese-in-the-SCA board), a couple professional web developer/ linux ones, Vintage Erotica Forums, Brass Goggles (a steampunk forum), and a couple South African-specific ones like MyBroadband.co.za.
Of course here at the SDMB, and I also post on the AFBlues forums as AFP.
I’m Clothahump on everything except martial arts boards, where I am Balrog.
Here
Mellophant
Giraffe Boards
Numerous forums over at Delphi
Unofficial ATA Message Board
MartialArtForum.net
TKDSpace.com
My usernames get less creative over time, starting with Weirdguy as my first Internet email address in 1994 (based on my BBS nickname from the late 80s The Weird Guy), then Canuckguy (when my wife thought I shouldn’t be thinking of myself as “weird”) - where I’m still registered as at Wikipedia (though that isn’t an “Internet Forum” per the OP) to dhkendall being my nom de geek pretty much everywhere now, including the Forums I go to the most (well, really, the only two), here and the Jeopardy! fan site (fan from way back, actively trying to get on the show - I know other Dopers have (curious as to which, but won’t officially ask here as that’d be a thread hijack, might start another thread asking somewhere, most logical place would be the Cafe))
SDMB (duh)
iboats.com (boating)
Various skeptic and science sites (I lost track of how many).
rcuniverse.com … Inferno GT pro boards and numerous remote control vehicle forums
offshoreonly.com (speed boats)
speedwake.com (speed boats)
Avaya pro boards
I am Philster on all the boards.
I lurk on a lot of forums like jref, etiquette hell, and jezebel. But the forums I participate in a lot are on Fark, Beer Advocate, LibraryThing, and Comics Curmudgeon.
Oh, how could I forget Comics Curmudgeon? I’ve known the guy who runs the site for years before the CC existed, and was more active on it before (but still usually didn’t have time to read all the comments or comment myself), but now only check the site about once a fortnight or so. 
Just because I’ve been too busy for this fine site doesn’t mean the rest of y’all shouldn’t be!
This reminded me of another similar one (although this and CC are more blogs than forums) that I used to frequent more, but now not so much, Strange Maps - being a geography geek, it’s only natural.
SDMB and Golden-road.net. The latter is a message board for fans of The Price is Right. It also includes rare photos of behind-the-scenes stuff, information on each of the pricing games, and a timeline listing various events and game debuts from the premiere in September 1972 up through today.
I dont’ know if I’ve ever listed them, lemme try.
Here
Mellophant - Brewha
Giraffeboard - Brewha
Hondashadowriders - MotoPsycho
Spadworld - Gravityisnotmyfriend
RCUniverse - Gravityisnotmyfriend
RCgroups - GINMF (length restriction wouldn’t allow Gravityisnotmyfriend)
KawasakiTrax - Brewha
JeepHorizons - Gryphon
MTBR - Theonlyusernamenottaken (I ran out of ideas)
Geocaching.com - Brewha
SnowmobileForum - L.T. Grey (I have an Artic Cat El Tigre)
SnowmobileWorld - L. T. Grey
Yes, they are all current usernames. Though some are seasonal. I’m on the snowmobiling ones now more than the motorcycle or RC Airplane ones.
ETA
Lumenlabs - GINMF
DIYProjectors - GINMF
SDMB
Lizzie Borden Society Forum
Magic Cafe
Visit those just about daily, though don’t post as often as I did when I first joined them.
Also a virtually non-participatory member of:
Buskers Cafe American
The Scoundrels Forum
The Genii Forum
The Cups & Balls Forum
Oops, I forgot about slednutz.com - but I’ve only got a couple of posts there.
SDMB*, Snopes*, SFF.NET, SFWA.org, IMDB boards, Giraffe*.
*Login as “RealityChuck.” On the others, I use some version of my real name.
I don’t post a whole lot anymore anywhere, but
Mellophant - SilverTygerGirl
Whitechapel - Silvercat
Customerssuck - Silvercat
ImmortalGeisha - Silvercat (it’s a kimono & geisha board)