1. HSDPA/HSUPA/UMTS: Particularly the 850/1900 MHz bands allowing for internet access wherever there is a 3G signal.
2. Wi-fi: Wi-fi is particularly useful when there is not very good 3G coverage and is good for accessing your home network and/or school network without worrying about limits on data and/or performance issues from too many users using the 3G network.
3. 3.5 mm headphone jack: It is nice to not worry about bringing along your headphone adapters when you are out and about with your mobile phone, just bring your favorite set of headphones and your mobile device and you are good to go enjoying music in its pristine quality.