Buying and Selling Stocks/Investments

I've been researching those different sites, and why Im curious what others think that may do this.

I've just been looking for something different since myself and my wife each have pretty good retirement accounts going. I've been on some of those Lending sites, but the return is pretty low and also slow. I would like to play a little bit with some extra money I have to see how it goes.
Why not build a gen 2 hemi w/ the extra $$ ? street fuel inj., alum. headed roller cammed about 600 cubes or so --------------------lol