My response: We absolutely need to do that.
The link my mom sent me was from Art Bar, which is an excellent resource. The idea of smash painting is that you put paint (preferably, very washable paint) onto a cotton round and place that on a larger piece of paper (we used 5x5 flat canvases). You then strike the cotton round with a hammer, mallet, meat tenderizer (that last one happens to be one of the things we had around the house). The paint then splashes and creates an abstract painting. You can overlap the colors, creating quite an artistic smash effect.
Of my three children, Clare had the most fun with this activity. She used the hammer to smash her paint and it splashed beautifully. She took great care choosing her colors to create a certain ambiance for each canvas.
Meg gave up on this activity quickly and opted for doing an abstract painting inside the house on her canvas (it was a hot day). She and Clare developed a painting technique where they squirt colors on the canvas and carefully swirl it around with a palette knife. Anne's approach to smash painting was more of a smash and smear technique. She then moved to painting mermaids. Hey, whatever. At least everyone was being creative.
Here's a few photos of our smash paint adventures.