Yes, both domestically and internationally, had no probs travelling with lights in carryon, on person, or in check in.
Nothing big or fancy. Recent trip, I had a RiverRock 2AA, and a coupla Dorcy 1AA modded with a 1/2 Watt 8mm LED and coupla Dorcy 1AAA modded similarly.
Once, they did ask me to turn on the RR, turn it off, take batteries out and then turn on again. ...which was weird but I guess they were checking to see if the batteries were suspicious dummies and the light was modded on some other hidden battery source. [woulda shown up on xray, though, hmmmm]
So I concur with the previous posts, should be no prob...
Good Luck!