Hi Debjh...
I first heard of them last year at a fitness conference and have taken a couple classes using them at Crunch, NYC. I love them!! They are one of the few "new fitness equipment" that has great potential. If you dont' want to fork out the money you can always use styrofoam plates as well as the gliding discs are nothing but "little frisbees". But yes there are definately some great core exercises you can use them for!
