Rebtel looks good but I have a question and didn't see the answer on the rebtel.com site. When you call someone, they see a number which they use to call you back. Does that number change every time or is it assigned to you? If BF calls my landline, I don't have caller ID so I wouldn't be able to see the phone number if it constantly changed. I'd have to have him call my cell to see the number, then I'll call him back on my landline which I always prefer.