I am currently using them on my Aluratek Cinepal media player (which is not so great BTW, which is why I haven't yet done a proper review of it) but again, I have to use a card reader to transfer media onto it. I hope they don't wreck the SD slot on my reader for other SD cards.
Why the heck are they so much thicker than other SD cards? It's bizarre and annoying. There should be a standard spec for SD cards that all brands should adhere to.
Maybe that's why Kingston cards go on sale so often...