A Gobo is used to create shapes of light on a subject. It's usually quite a hassle, but the StrobePro Optical Snoot has changed the game.
You can actually mount a lens to this light adapter, add whatever shape you want and fire a light through it to create different light shapes for your photographs. In the past, you had to cut shapes out of a poly board, get a separate stand for it, have enough space to move the light further away from the board in order to get the desired effect. Now it's all in one package, with one light stand, one mount and a much quicker way to change the shape.
Due to the fact that the light travels through the lens, you can change focus, so the light shape can be blurry or sharp. You can also mount different types of lenses, where a wide-angle lens will give you a very different shape than a portrait lens would. It's rather pricey, but if time is money, and you want to get to shooting as soon as possible, this snoot can be a game changer.
I suppose Gobos aren't for everyone, but if you want to explore it, and you would like to add this to your style of photography, it's the newest idea I've seen in the past few years, and I think it'll give you as photographer much bigger scope, especially if you know someone who can cut out metal sheets with custom shapes on it. Imagine your name, or a brand's name, or abstract shapes, and then adding different gels on this light and combining it with a different color gel on the key light. It sounds like a lot of fun.
Check it out here.