MY IPHONE 4 screen randomly gets so enlarged that it becomes inoperable. I can not turn it off anymore even in order to reboot. HELP!!!

Hello there, lulupeachy.

It seems that you've zoomed the screen using your iPhone's Accessibility feature. The following Knowledge Base article provides some great steps for how the feature works and using it to get your screen back to normal:

iPhone and iPod touch: Home screen icons are magnified or large

http://support.apple.com/kb/TS3129

Particularly:

1. On the Home screen, double-tap with three fingers to exit zoom.
2. Locate and tap on Settings > General > Accessibility:
   
3. Tap Zoom and turn off using the slider:
   

For additional information and assistance with accessibility features, refer to the iPhone User Guide or iPod touch User Guide.

Thanks for reaching out to Apple Support Communities.

Cheers,
Pedro.

Had the same problem, just double tap the screen it will go back to normal. then follow the steps above and turn it off.

Hello again, lulupeachy.

You're welcome! I'm glad the information helped resolve your issue.

Sincerely,

Pedro

my iphone5 does that.. yes the triple finger tap -- who could forget that? me of course:))

Thankyou very much, i'd forgetten about the double tap with three fingers...............Dave.