If, for whatever reason, you've decided that simply biting your fingernails isn't the best way to keep them short, you'll want to invest in a nice trimmer. But not some giant monstrosity that requires a purse or a murse to keep it on hand. Go for Kershaw's ultra-thin nail clippers that fold down to an easily pocketable 4mm package.
When collapsed, the clipper looks even smaller and thinner than a USB flash drive, but it still manages to pack a trimmer and a nail file into its discrete form factor. It even comes with a leather carrying case, but since it appears to add pointless bulk to this sleek creation, you'll definitely just want to carry the $42 clippers naked. [AssistOn via Damn Geeky]