Conference call, merging of calls, etc
I don't know if this is an ICS bug or a Samsung bug or a Verizon limitation? When making a phone call it is very easy to add another phone call and merge both calls into a conference call. But if one of the calls drops off, there is no way to add them again. There is also no way to hang up with only one of the people on the conference call, you have to end the whole thing.
This probably is on a stock Galaxy S3 on Verizon with the default dialer. I tried a different dialer but that function seems to be outside the dialer.