Ohh, he's your husband, you should KNOW him
So,, think about what you know about him... what does he like? What does he enjoy? What might he like if given the chance?
If you are looking for something outrageous: flying lessons.
Obviously, tools, books, clothes, stereo, Cd, car toys, "neat" gadgets, barware, movies, magazines, candy/nuts, electronics, sporting goods, are all popular "MAN GIFTS"
Give him something sexy: condoms, sexy movie, a thong (for you) a voucher for babysitting, a pack of polaroid film or video tape: Most husbands wouldnd't expect that in thier stocking!
A leather coat, a canoe, a DOG, a special coffee mug, a trip, tickets to a sporting event...
Gosh, if you just take the time to think of WHO your husband is (adventurer, sportsman, couch potato, father, lawn guy, mechanic, computer geek, lover, outdoorsman, health fanatic, party guy, cook, coffee drinker, OR whatever-- I could go on and on!!!) You'll be able to come up with a good gift!
Good luck.