A follow-up to Maxgain's suggestion: if you decide to use Vibrapods, be sure to put something between the Vibrapod and the ceramic tile. Over time, Vibrapods will stain many kinds of materials they contact. Something like a small, thin plastic disk, or even a piece of Zip-lock bag material, will suffice. (I used Vibrapods on an oak shelf, for example, and they permanently stained the wood.)
The other choice which has not been mentioned is an adhesive like Blu-Tak. Blu-Tak, however, is relatively expensive -- about $10 for a pack. For about $1.00, you can buy the same stuff at Office Depot under the brand name "Tak 'n' Stik", manufactured by Elmer's and other companies. I use "Tak 'n' Stik" under my surround speakers and center channel speaker, and find it works very well.