I cant unlock my iphone 4! Help?

I was playing around with my settings, and I think i turned on voiceover… Or something like that. Then my phone started talking to me and it freaked me out, so I did what any sane person would do and I pressed the power button. That stopped the phone from talking to me, but when I tried to unlock it again there was a grey box in the upper left hand corner and my touchscreen wouldn't work… So I cant unlock my phone. If anybody with an iphone thinks they have any idea whats going on can you Please help me?

Drink your own farts:)

Wej kan not open my iphone