I don't usually wear a tie, but if I did it would invariably find a way to dip into in all sorts of things.
I also don't work in an office so most of the things would be probably be liquids.

A moisture sensor in the tip of the tie activates a smallish canister of helium to rapidly discharge into a balloon concealed inside the widest fold of the tie.

As the balloon lofts my tie safely out of harms way I can thoroughly enjoy my night out secure in the knowledge that looking like a complete idiot was narrowly avoided.
-- 2 fries shy of a happy meal, Nov 13 2009

got one for you + http://farm4.static...9181_e3a0640180.jpg
[xandram, Nov 13 2009]

Prior art http://www.quia.com...AGES/DILBERT-TIE-UP
[normzone, Nov 13 2009]

random, halfbakery