I can think of 100 different instances where one would be convenienced to be able to use voice and data at the same time.
Length really doesn't matter if you are looking something up on the spot.
To debase something by putting the adverb "just" in front of it is the lowest form of justification. It explains nothing about why you shouldn't regard it as highly as you do and is thus used by the academically-uninclined. The phone is something people have with them at all times. It's how they keep up to date with current events, pop culture, and social networking. It's how they keep in contact with the rest of the world. To say its "just a phone" is uninformed, falsely supercilious, and weak.