Camouflage is a freeware plug-in for PhotoShop compatible plug-in hosts.
It will work with applications such as Adobe PhotoShop, JASC Paint Shop Pro, Corel PhotoPaint, ULead PhotoImpact and MicroGrafx Picture Publisher amongst many others.

With Camouflage you can easily create any type of camouflage texture you desire, ranging from authentic WW2 army vehicle camouflage patterns to modern-day NATO patterns to animal textures of various types.

You have full control over the look and feel of the effect; scale, blurring (the smoothness of the spots), falloff (how much area each color layer should cover), up to 8 different color layers and a random feature, allowing for 10,000 different patterns.

All textures generated by the Camouflage plug-in are seamless and can be wrapped for use in web background use or 3D graphics and since the pattern is automatically scaled to the image size, you can even use it to easily create mipmaps for use in real-time 3D applications.

There also a large list of common, authentic (WW2, NATO) and animal color presets, based on actual patterns.

This plug-in is free to download, so you have no excuse to not try it yourself!