I've flown alot recently, including twice since the Britain Threat. The extra security is not an inconvenience. Infact, i've found that security lines are actually shorter because people are sure to put anything that might cause question into their checked baggage instead of holding up the carry-on checking lines.
If anything, the extra security is a reminder that we are at war and there are fanatics trying to hit us, the extra security reminds us of terrorism and what are we figthing against, and that America still needs to be on both the offensive and the defensive.
i'VE FLOWN SEVERAL TIMES SINCE 9/11 (oops sorry for caps), and I have had similar experiences, no griping, or whining about long lines, and actually the lines seemed to move along well. There was, everytime, an aroura of calm and I don't know about everyone else, but what I was thinking, while waiting in line to be searched was, "this is the fault of terrorists, we are at war!" I assumed everyone else was thinking similar things.