@JessicaLynn - You probably know about plenty of other 3G formats they've just become so commonplace you don't notice them anymore. A good example of is a mobile wireless hotspot.
A mobile wireless hotspot creates a portable wireless network that a few devices can connect to. Mobile hotspots usually take the form of a USB device or a standalone transmitter.
Even some cell phones can become portable hotspots (though this usually costs extra per month). 3G is also available on devices such the iPad and ebook readers.
3G is pretty much everywhere these days even though 4G has arrived. I think it will be quite awhile before 3G is phased out in favor of 4G.