Heres a fun little trick. It's not really that complicated of a chemistry experiment. All you need to do is take a bottle of cola (I did this with Pepsi) and drop a Benidryl pill inside. Then close the cap very tightly and be prepared for the typical reaction that you get when shaking a bottle of pop, only you get more fizz, which means more pressure. You can get creative afterwards. BTW I don't think it's such a good idea to drink the stuff after putting medicine in it. Also remember to use common sense when trying this. Another fun addition is to slip the cap, then you have an automatic cola squirt gun!