I want to get a smartphone but am confused by all the features - which ones do you think are important?
Um, I think the Apple IPhones are pretty important. You get to download whatever apps you want because of the iOS mobile operating system.
That sounds interesting - are there other operating systems besides Apple?
Of course. My favorite is obviously the iOS by Apple, but the other one that comes to mind is the Android mobile operating system. It's basically a modified version of the Linux kernel and it's open source unlike the iOS. 
Do both iOS and Android have things like instant messaging and facebook?
Yes, I'm pretty sure they do. Most mobile operating systems have features such as touchscreen, cellular and wifi capabilities, Global Positioning System(aka GPS), messaging, music player. I'm also sure you could access Facebook through the web browser apps.