OK, here's the definitive TSA "Can I take it, can't I take it" list.
http://www.tsa.gov/interweb/assetlib...-1-2005_v2.pdf
(Corkscrews, nail clippers, nail files, plastic cutlery all get an unequivocal "Yes".)
The common sense evidenced by the list is diametrically opposed to virtually all my experiences with TSA and similar organisations (and I have to say that UK airports are top of the list for small-mindedness and sheer pettiness. Not to mention officiousness)