Each year the Rat Rod Bikes forum has a build off competition. The rules are pretty simple, minor frame mods are allowed but significant frame alterations arent (its like saying a body kit is okay but body drops arent). Paint needs to be applied by the builder, and budget builds are encouraged. This is basically to keep the field somewhat level otherwise the guys who can create a scratchbuilt frame would win every time. Anyway, the whole idea is to encourage people to make a cool bike, maybe go that extra step in making it cooler, and have some fun friendly competition.
The full gallery of bikes is here
And some I've cherry picked cause I dig them