A solution to one of the problems that motivated me to search for a clock radio -- using the cell phone as an alarm clock puts you at risk of being awaken by crank/marketing calls. The solution is simply to use "airplane" mode, which still allows the alarm to ring at the appointed hour, but prevents any calls (incoming or outgoing). I'm not sure if airplane mode is specific to my el-cheapo Samsung phone or not, but it sure sounds like a feature that many phones should have. Note that I'm not saying that Samsung phones are cheap, just my model.
My Kyocera has airplane mode, but I've never been on a plane with it (Most American phones won't run in Germany, so I left it at home), so can't tell you how it works as an alarm, but if your Samsung is running Android, probably similar.