Here's my student Lydia Koch's wonderful Math eNotebook assignment on pennies which started the penny fractal idea. Isn't it an amazing coincidence that her last name is the same as two of the fractals!
Cool Math fractal page , and here's the NCTM fractal generator.
Of course, the sky is the limit when it comes to fractals so here are a few more really cool fractal links.
The Fractal Foundation,
Vi Hart's Fractal fractions.
Fractals in Nature