What, besides APS and THR.us (haven't been to .org for a while now, come to think of it)?
I've been known to spend time at I Can Haz Cheezburger, though I haven't been there for a while. Not so much a forum, of course, as just a bunch of silly captioned pictures.
Flyertalk.com's Travel Safety & Security Forum (
http://www.flyertalk.com/forum/travel-safety-security-222/), where there is much discussion of TSA's latest and not-so-greatest travesty on a regular basis. Mostly anti-TSA (no surprise, as most of the residents are frequent flyers), but there are a few TSA apologists there, a couple of whom claim to be screeners for the agency. I also hit FT's Omni boards occasionally.
I'm an irregular Barfly at Baen's Bar, the forums for Baen Publishing (mostly milscifi books, for those here who haven't heard me hyping their Wbescriptions and Free Library yet
) at bar.baen.com.
Because I'm a costuming and prop geek:
501st Legion Of Stormtroopers (
www.501st.com, with 501st-member-only forums at
www.501stforums.com) - the world's biggest and best Star Wars costuming group. We're the ones in the Guiness Book, we trooped at the Rose Bowl Parade a couple of years back when Lucas was the Parade Grand Marshal (Lucasfilm Ltd. brought in 200 troops from all over the world for the event, at their expense), and we're the go-to group for SW book signings, game and DVD releases, movie premieres, and assorted charity events - as a result of which, Lucas wrote us into SW canon for Episode 3 (the blue-striped troops that attacked the Jedi Temple with Anakin were the 501st Legion). Been a member for 8 1/2 years now, and the group just keeps getting bigger - over 5800 worldwide, at last count.
Garrison Tyranus, the Virginia chapter of the 501st (
www.va501st.com, with reg-required forums at
www.va501st.com/forum - prospective members have full access to the forums).
The Rebel Legion, sister group to the 501st (501st does the bad guy costumes, RL does the good guys -
www.rebellegion.com, reg-required forums at
www.rebellegion.com/forums - site appears to be down at the moment). Freedom Base covers VA, as well as DC and WV IIRC. Not as big as the 501st, but not too shabby - better than 2400 worldwide, last I saw. Lots of members of the 501st are also RL members, myself included.
Been a LONG time since I've been there, but I'm a member at
www.scifihero.net, which got its start as a Stargate fan/costuming group and branched out from there - there're probably at least as many new-BSG fans/costumers there as Stargate ones, for the past several years.
Someone else mentioned Club Obi-Wan up above (
www.indygear.com/cow) - I got a discount on my Indy jacket from US Wings as a result of being a COW member. Bought my Akubra Federation IV (an Aussie-made Indy-style fedora, VERY accurate and excellent value) on the recommendation of numerous COW members.
The Replica Prop Forum (
www.rpf.com) - perhaps THE best source of information on costuming and propbuilding out there. Several industry professionals stop by on an irregular basis, and some are members (such as 'Mythbusters' Adam Savage). Iron Man costuming's really big right now, so I'm spending plenty of time there lately. You can read without registering, but cannot post - registration only happens a few times a year, IIRC.
The 405th Infantry Division (
www.405th.com) - costuming/fan club for the Halo video game series, with tons of information on a costume-building technique called pepakura (means "paperfolding", IIRC - you can take designs, make them out of folded cardstock, and coat them with resin and fiberglass and detailed bondo to create awesome-looking durable costume armor). Also a lot of Iron Man talk there.
There are other sites I hit VERY infrequently, but those are the most common ones.
