In October 2004 I traveled from Chicago to Portland (OR) to San Francisco roundtrip without any ID (forgot my driver's license back in Chicago) and carrying on a 1520 Pelican Case containing two lenses, lensboards, shutter, boxes of film, Polaroid 545i, my Toyo 45AX, and even a scary looking shutter release. I was also carrying my Bogen Manfrotto 3221W tripod with 3047 head, and the three-way head arms with threaded ends were in the Pelican case. I was also carrying a Brenthaven backpack with a laptop.
Although getting searched was no problem (the folks were even friendly and very fascinated by my 'old-fashioned' gear), the delays were significant (15 minutes to get the full search). Had I remembered my "government-issued ID", this delay would have been non-existent, but I've had no trouble getting all this equipment through security and carried on to several airplanes on several occassions.
On my way back from California (Yosemite) I even tested positive for a military explosive known as Cemtex (sp?), which the officers told me could not have been contracted through chemicals in a darkroom (that was my only guess). Nevertheless, after a few minutes of conversation the friendly officers at Portland International Airport let me get on the plane, equipment examined but unscathed.
My lessons were (1) remember my ID and (2) think about buying a lighter tripod! ;-)