You know you look like a tool, right?

I've found it.

I've found the one accessory that is so powerfully wrong it can take an extremely well-dressed woman with excellent posture, Marc Jacobs peeptoes, near professionally-applied eye makeup, Reese-worthy hair, Laura-Linney-worthy skin and a set of 20 perfectly shaped, short black nails from a Britney during this stage to a Britney during...well, just click here.

Of course, the accessory to which I am referring is the ubiquitous, makes-anyone-look-like-a-giant-tool Bluetooth headset.

I don't own one of these devices, so I can't say for sure how easy or difficult it is to forget it's clipped to your head, but judging from the size of the one this woman at the Cosi on 20th and M had harnessed to the side of her face this afternoon - it was literally the size of my Treo - I have to believe she knew it was there. In a painfully well-cut black pinstriped pantsuit, the black and ivory polka-dot cap-sleeved blouse with Peter Pan collar from Banana Republic with which my lady goods weren't able to make peace at button four and the aforementioned Marc Jacobs heels, this woman, based on the way she was dressed, really should have known better.

Even if she had been mid-conversation (she wasn't), it's just plain unladylike to order anything, pay for anything, talk to someone, or be in a position where you might have to talk to someone with a gadget two inches from your face.

Well, certainly not every kind of gadget.

Anyway, if looking like the kind of cold shrew who doesn't "repay the favor" isn't convincing enough, let me be completely honest and tell you that as beautiful as her poppy Kate Spade London bag was ($415 at katespade.com), even its custom nickel hardware, intensely Communist-red pigmentation and structured-but-not-intimidatingly-so silhouette weren't enough to vitiate the get-over-yourself eye-roll her headset elicited from even the toddler standing next to me.