I usually don't bring any kind of products with me when I travel - but my mom is an absolute fanatic about trial sizes.
She's the kind of person who would come home with a tiny bag of trial-sized dog food because the package was "sooooooo cute" even though we didn't have a dog! :)
And I am old enough to remember when trial-sizes really were to test out the product, and they were given away free or for a dime. Then they went up to 49 cents and now the cost more, unit wise, than the full size product.
Anyway - Mom likes to outfit their RV with trial-size condiments. She claims it is to reduce weight and thus improve gas mileage, but I still think she just likes the packages. She loves those little ketchup bottles that they put on the room service tray and I found them to buy on this website called http://www.minimus.biz/
Minimus has thousands of trial sized packages of just about everything you could want. And not just food - I found laundry detergent, otc medications, body lotion, all kinds of stuff. They also sell "gift baskets" of a sort, to send to troops overseas, etc.
And I know some people bring along their own toiletries so I thought some people might find that website useful.
I did make one order from them, and I got free shipping due to the amount I ordered - I didn't look to see if they still had that deal or not, but you might try looking for it.