Many people use figurines to represent their characters in a game. These can range from generic moulded figures simply left as they were purchased, to heavily customised figures with paint jobs and sculpting modifications. (One ultra-nerdy and hence ultra-cool option is to use LEGO figures, which can be easily customised with their various accessories. This is an even better choice for many roleplaying games with recent releases such as the Star Wars and Lord of the Rings LEGO sets.) These figures help the players and GM visualise the relative positions of characters during tactical situations.
You can of course go the whole hog and custom sculpt your own figures from scratch. At the very least, they will be distinctive.
GM: Sally, Corey, you were discussing blue milk.
Yoda: So, fieldhopper, the milk or the stew?
Luke: So... What did Obi-Wan pick?
Yoda: Heh. Formulate the recipes, he did.
Luke: Ah! You know Obi-Wan. You're Yoda, aren't you?
Yoda: Well done, young Padawan.
Luke: What's a Padawan?
Han: It's not what you'd think.
Luke: You know, it would have been nice if Obi-Wan mentioned you were a small green... thing.
Yoda: I made that sculpture six years ago!
Yoda: It was originally supposed to be Ben, but I got a bit carried away with the ears.
R2-D2: You got the nose perfect.