I found this quite interesting. I have an iTalk number and my mobile phone number with CallerID blocked on both. I called my slingshot landline via both of the numbers, and even though they came up as UNAVAILABLE under called ID on my phone, I was able to use slingshot's "who called me" feature to find the numbers that had called.

Is this to say that my number isn't really hidden? I thought it would keep people from learning my number as I'm very tight on privacy, but obviously not. Is this normal? Isn't hiding your CallerID pointless if people can just find it anyway?