For instance, my new laptop has Bluetooth built in. There is a phone that I want (SE T616) that has Bluetooth built in as well.
Because of that, I can upload all of my contacts on my computer up to the phone. The phone is a picture phones, so I can take pics and send them over to the computer.
I can use the phone to control the iTunes on my laptop like a remote control from around my apartment - and it will send the song info to my phone screen so that I can see what song it is, etc.
I can also then use the phone as a modem and get a net connection with it.
All of those are things that you could do with wires before - but now they are all things that are wireless.
Wireless essentially means less of a hassle in terms of things to hook up, and also increased distance at which you can do it.
There is also a new game with those phones to send messages that way to other phones - the phone basically scans the area around it to see if there is an open Bluetooth device that is configured to accept messages and then you can talk to it via certain ways.