However an entymologist friend at AU told me this: If you pick them off and mash them right under the bush, they'll emit a pheromone that warns other hornworm egg-laying moths (?) that it is A Bad Place, and over a bit of time you'll have fewer issues with them. You have to be persistent tho, one mashed worm won't do it. And you have to do it under each tomato plant. Granted, if you have 100 plants this could be tedious, but I only have 6 and it is satisfying (in a really nasty, sick kind of way) to pick them off (with tongs, I cannot touch them for it causes willies) and squish them. Sometimes I have to pay my 11 year old to do it for me.
