I don't own any crackle polishes yet, but boy do I want to. Loads of brands are coming out with crackles now. Shall we begin? China Glaze, for example, has 6 colors:

Head2ToeBeauty sells these for 3.49 each, 8ty8beauty sells them for 3.18 each, Transdesign sells them for 3.20 each, and I found them on Amazon for as cheap as 3.80 each. If you want to buy it in store, Sally Beauty and Ulta should both be carrying it soon, as I don't see it on their web pages.

Crazed Expressions has an awesome collection of 20 shades. They look pretty sweet. The only bad thing is I can't find them for sale...anywhere except Ebay. I sent them an email so we'll see if I get a helpful reply.

BYS also sells a crackle polish in 14 shades. They also come in little sets with a base color, the color of crackle, and a top coat too. You can buy this online at FashionAddict for 4.95 each. This is the only place I can find it.
This weird foreign brand that looks like BK has some cool colors that the other lines don't carry, like brown and some different reds. You can still order them from TrendInCosmetics for 6.00. I've heard that you can get them for less than 3.00, but I haven't found where yet.
Bornpretty, a store you should all be familiar with, sells 7 colors for 4.52 each. Free shipping! They also sell a lot of cute nail art stuff like rhinestones and brushes.
Barry M has a black crackle polish like OPI's, not to mention loads of other cute ones, but I can't find a single place in America that sells this. It's a European brand.

I'm really interested in how people will start taking the crackle polishes to new levels and doing some great nail art with it. The first picture is an example from Crazed Expressions. I founds some more that I will link to instead of posting them here since they belong to other bloggers. The Laquerista did OPI's Black Shatter over a holo
here, and over neon sponged nails
here.
So the crackle fad is spreading! Though many brands now make a crackle polish, it looks like the China Glaze one will be the easiest to get ahold of. I'd love to try all the colors from Crazed Expressions though.
Will any of you be purchasing a crackle polish, or have you?