I used to use mine all the time for music, email, calendar, and various apps/the internet. I loved using it at home and on campus, but I couldn't really use it to the fullest other places because it needs wifi.
I still use it all the time for music, but my iPad took its place for home use, and my smart phone (just one of those android phones) took its place out and about.
As great a device as it is, having Internet and stuff everywhere like on the iPhone (not just around wifi) is so much better. Also, then you don't have to carry two devices.