How to access the internet through wifi without a data plan on the blackberry curve 8900?

I have a Blackberry Curve 8900 (the new). I have no data plan, but I keep hearing that you can access the browser while connected to Wi-Fi. But every time I try to access the Internet via the phone, keeps saying I need a data plan to access the Internet. If someone told me how to solve the problem, I would be happy.

How to play high quality videos from youtube on the blackberry curve?

When I go to YouTube and watch a video of my BlackBerry video quality remains very low and I see the AC option, because usually if you go to a computer. Is it possible to play a youtube video quality on the BlackBerry and if so how? Thanks!