I was travelling to Singapore for a Business conference with a couple of other associates and on ones recommendation we used Clay sim cards for calling purposes and also for emails. It was by far the worst services that i have ever used!!! I am so glad that i had taken my Indian number for emergency which actually turned out to be the one that i used., cz the clay sim card refused to register any signals or calls. The data for which we already paid a bomb was acting like regular EDGE services! Guys its nthing but total disappointment using a sim from clay!!