Product review (5 stars): Yep, they work.
I've only been using them for a few weeks at this point.  They were easy enough to install... just lower the feet on the dishwasher, line them up, take the sticky tape guard off and stick to the counter top.  Then adjust the dishwasher feet and screw them in.  I can't see them normally, they hold the dishwasher in place, and really what more can you ask for?  I'd buy them again.

Update 6-25-2012 After 6 months, the dishwasher is still in place. I almost forgot they were there, this is a very good solution, would highly recommend.