One of our late-season tomato plants was recently attacked by mobs of spider mites. After getting photographic evidence and investigating disciplinary actions against said mites, we chose to go old school and used dogs and fire hoses on them. The dogs didn't do much other than wander around the yard, seemingly unaware of the mites (a crafty ruse on their parts, no?), but the hose blew the mites off the plant and we hope that's the last we see of them.
I had wondered if there were predators we could buy as the mites were gathered in huge numbers. For aphids you can buy ladybugs and the ladybugs will make short, delicious work of the aphids. Ladybugs are not recommended for mites. I think the size difference is too great. It would be like inviting guests over for dinner and serving them a couple of rolls of Sweet Tarts. Unsatisfying all around.
In any case, here is the photographic evidence of the spider mite assault, in case I ever need to present it to a grand jury. Even after cropping in Photoshop, it's still in reasonably high res. Click and enjoy.