While I don't have mine yet, I'm pumped to try out these:
Shake to search for Bluetooth Devices.
Double tap the top of the phone to get to the top of a list (ie Contacts).
If you want to just go to the source, you can read about all the features here:
http://downloadcenter.samsung.com/content/UM/201206/20120619155959211/GT-I9300_UM_EU_Icecream_Eng_Rev.1.0_120619_Screen.pdf