Re:Sous Vide Cooking
They're useful for commercial production cooking and high end gormet cooking, but for the home... I can't see myself using it.
I know a lot of places will put in 100-150 steaks, bring them up to medium rare and hold them right there for the night. Steak order comes in, pop a bag, slap it on a screaming hot grill for marks, and you can serve up a perfect med-rare every time in minutes, leave it on another min or two and it's medium. Big time saver in commercial production kitchens. (ie: banquets, conferences, weddings)