It is totally up to you what you decide to put your jello in. Usually, the jello is poured into 1 or 2-ounce plastic cups. The kind with the lids are a definite blessing, especially if you are taking them somewhere. The lids also make it much easier to display. Instead of having 40 or 50 jello shots lined up in military rows on your kitchen counter, with the lids, you can just get a large bowl or container, and put the load of them in there. Now you have room for the cheesy potatoes and nacho dip!
You can also always opt to use party cups, paper nut cups, or good ol’ Dixie cups. Just remember that the size of the cup will determine how many shots you will get out of each batch. Most recipes are proportioned using 1-ounce cups. It should specify if otherwise. You can also go with the more classy approach by using shot, cocktail, or cordial glasses. Glass will definitely give the desired look, but may be difficult to shoot from. You might want to provide little spoons. Paper cups are a bad idea, because they fold when the hot liquid touches them.
You can also just go pouring your mixture into a flat pan. Then you can either cut it into 2-inch squares, or get some fun shaped cookie cutters and serve up some hearts, moons, or stars to your guests! Let yourself get totally adventurous with these jello jiggler-style shots. Try lighting up the party with naughty adult themed jigglers and see what happens!