Consider as an Iphone, without the built in phone, or an Ipad with a smaller display/form factor.
Music. Video. Web ( if you have WiFi ) , Apps ( If you have Itunes or Wifi to the net and an Itunes account)
Apps = Games ( Angry Birds, Plants vs Zombies, Real Racing GTI etc) , Tapatalk = forums on a mall form factor device
You dont have to be tied into the Apple Format Ecosystem with apps like VLC and Air Video
It also makes a great remote / controller for other devices ( ipeng , remote etc)
A guitar fx box ( amplitube + iJam etc)
Its like saying what can I use a small form factor computer with built in wifi and a touch display for. Depends on the software you use.
EDIT: As to the Wifi - its a wifi enabled device , so the question becomes which wifi networks can i access?
you own at home - assuming you know you know the ID and wireless password?
Anyone who has still default passwords on their system http://www.phenoelit-us.org/dpl/dpl.html
Out and about - some businesses offer free wifi as a competitive advantage , some bundled with a purchase (e.g. coffee)
Typically you have to use the browser to login / accept terms and conditions to get network access.
You could also tether to someone else's device , or carry a mobile hotspot of your own.
It still functions without connectivity, but only for local content. Obviously.
EDIT2 : You have it , yet you can't determine the quality of the display, when the source image is not the limiting factor?