It's hard nowadays to find ways to get your kids, especially boys to sit down and work on something. Harder still to find something you can do with them and really take part in and contribute to. This is a fantastic thing you can do today to bond with your son and I really recommend it. Oh and it doesn't hurt that its really cheap to do!
The online coloring stuff with printable option might be the best of its kind as the child does not have to finish his coloring in one go, he can wait and try his hand whenever he wants to. Or he can get the prints once he is done with the artwork online. What pleases you more? The child who is happy and busy or the one who is always complaining of not getting the stuff he wants to color. Of course the latter option can be the choice.
Oh and then when we got to our destination, the coloring pages were given as a gift to their Nan - so you can see how great this simple hobby is!