When you hear juggling, you usually think about someone with 3 or more balls. At least that is what I did. And if you want to learn how to juggle, you should start with balls. To learn the system, these are the easiest. And clubs, rings, cloth, torches, etc, use the exact same system (Except the clubs have to be flipped as well, for example). Almost anything that you can grip and that have a fair weight can be juggled. Being bored? Pick up some rocks, start juggling with some cucumbers, dish brushes, teddy bears, food, anythhing.
If you would like to get started, you can for example head over to the The Internet Juggling Database or just Google for it. There are bunches of pages about this.
Below is a video from the WJF Balls Competition 2005 and one with a famous juggler called Jason Garfield. Pretty cool stuff 
Fire balls
Fire balls are pretty cool, and kinda scary. I think they are made of a metal’ish core, but the important part is that they are covered with a layer of Kevlar. You dip them in, for example, lamp oil and then put them on fire. While juggling you wear a pair of Kevlar glows dipped in cold water, which prevents you from getting burned. At least as long as you only touch the balls with your glove covered hands, and re-dip your hands in cold water once in a while
