Is it possible to block a caller on your phone? For about a week, I've been receiving calls on my cell from a 1-800 number at roughly the same time. I tried answering the first time he/she called, but there was no reply. It's starting to get a bit annoying. So, is there any way I can block the number through the phone? Or will I need to have my provider (AT&T/Cingular) block the number? If it helps, I have a Sony Ericsson T306. Thanks in advance.