This is directly from the TSA website.
Common Lighters - Lighters without fuel are permitted in checked baggage. Lighters with fuel are prohibited in checked baggage, unless they adhere to the Department of Transportation (DOT) exemption, which allows up to two fueled lighters if properly enclosed in a DOT approved case. If you are uncertain as to whether your lighter is prohibited, please leave it at home.
Torch Lighters - Torch lighters create a thin, needle-like flame that is hotter (reaching 2,500 degrees Fahrenheit) and more intense than those from common lighters. Torch lighters are often used for pipes and cigars, and maintain a consistent stream of air-propelled fire regardless of the angle at which it is held. Torch lighters continue to be banned.
Bottom line, if you're looking for the letter of the law, you aren't allowed to carry on a torch, and you're not allowed to check one either. If you aren't willing to lose your lighter, you're really best leaving it at home. I lost one a couple years ago, but it was a CI freebie, so I didn't really care. For me, I never, ever check my smokes, and always check my cutter. Smokes stay with me, and it has been my experience that once a screener sees the travel humi, they tend to look for a lighter or a cutter until they find one. If they'll take a pair of nail clippers from a Soldier carrying an M16, (and they will), they'll take a cutter.