I bought an 12V vibration motor from China off of eBay, originally to see if it could help tamp down the loose ballast on my layout modules before fixing with glue.

The motor, even on a 9V battery, vibrated the board so much that all the ballast soon was one stone thick in a layer several inches wide!
Well at £3.97 inclusive of postage it was not a big loss.

Then today I wondered if it could help me mix paint! I wanted to thin down some tube acrylic paint for use in my airbrush.
I mixed the paint 50/50 with thinners in a disposable plastic bottle and fastened it to the vibrator with an elastic band.

Result? A nice creamy paint mix!