What is the best “shot glass replacement” for sake bombing?

We are throwing a “sake bomb” party this fri for about a hundred people, needless to say I don’t have 100 shot glasses, and even if i did, glassmay not be the best thing for a party of this type. What is the best thing i can use instead of shot glasses? (or maybe somewhere to get a whole lot of shot glasses really cheap and fast)
problems in the past include:
-people having to share shot glasses
-things like dixie cups floating and not allowing the sake to mix with the beer
-lack of availability
Or any other suggestions for a great sake bomb party.