One mans junk is another man's treasure, i think...I love trading swag...the first couple hundred of caches I traded everytime, now I'm a little more selective. I have a shoebox of my favorites over the years and often go thru it just to admire...one of my favorites was a a fist carved from wood. I look forward to sharing my "treasures" with my son when he's old enough.
Now I trade for items I know he'll play with, right now he's really big into matchbox cars and army men. I went online to one of those teacher "prize" sites and bought a big box of colorful erasers. I often leave a couple of those even if I haven't taken anything. I also usually keep a bag of swag in my backpack of items I'd like to receive. I can't ever imagine wanting a used ticket stub, but I've heard of people that have collected them. As for golf balls, when I was younger my sister and I had a collection of golf balls. We collected them whenever we found them and used them to dive for in our pool. If I see tennis balls, I take those, since I have three labs. As long as it's not garbage (broken glass, crumpled up paper, etc.) I think it's worth being called swag.
Also, I'd like to think on a very small scale I'm known around my area for having cool swag in the caches I place. I usually have a blast going to the store to stock a new cache. I've gotten new boxes of crayons, fun colored post it notes, deck of cards in the shape of a bunny's head, miniature bowling ball game...etc...all still wrapped. I had never thought to go out and restock my caches once in awhile until I read this forum, but now I think I will. Thanks for the idea. There's my 2 cents.