I saw this demoed on a cooking show/shopping channel, and think it's a pretty handy looking gadget. It works like scissors. The host was snipping thru squash, carrots, yams, a whole bunch of celery (at one time), over a large bowl. I may talk myself into it. It has a little lock/safety catch.
Scissor Slicers (Knife & Cutting Board in One)
An ideal kitchen cutlery companion that combines a knife and cutting board. The Scissor Slicer tool makes cutting fruits and vegetables easy, fast, and convenient. It operates with a squeeze-and-release action similar to scissors to simply slice through all of your foods. Comfort grip handle. Top rack dishwasher safe. Hand washing recommended. Set of two.
You can find it at QVC.