These were the temporary hot collectible item about 10 years ago. AKA milk caps or bottle caps, I also have the "slammers" which were heavier and used similar to the larger marble in playing marbles. I have tubes for storage that I also use for casino chips. Here is a sample of what I have:

I have all kinds of sets from Star Trek to Simpsons, Mortal Kombat, Michael Jordan, McDonalds, Power Rangers, Bad Boy club, DC Comics and on and on. I have un cut pog sheets and pog cards from Taco bell with sea animals, and Tombstone pizza with Dallas Cowboys' Emmitt Smith and 49ers' Steve Young. Let me know if you would be interested to see more pics or if you have some yourself that you would like to get rid of. These are all approx. 10 years old. Thanks for looking. # R-6666