How do I fix a broken iphone screen?

SOURCE: cracked touch screen

You can replace the screen yourself, or have a company replace the screen for you. If you are patient and handy with tools, I would purchase a new crystal screen (just the screen without the LCD\Digitizer), and replace it yourself. If you order from a company, this will cost you almost $200USD. There are tips online on how to replace the screen yourself with a plexiglass screen, but I'm assuming you don't want to do this.

self repair:
http://www.youtube.com/watch?v=X1z0pw2VK7M

professional repair:
http://www.rapidrepair.com/shop/apple-iphone-repair.html

SOURCE: My iphone is broken

Take it to a Apple store they might be cool to take it in and replace it. I know my friend just doesn't mind.

SOURCE: Broken touch screen.

The screen can be replaced by a tech savy user and the part is available on common auction websites. There are iPhone Repair guides that show you how to do the replacement with a series of pictures and written descriptions of the necessary steps.

SOURCE: Cracked Iphone Screen

You should have LCD Replaced.!
And there is another place with best price quaranteed www.buyforapple.com

SOURCE: broken glass touch screen to iPhone

It's a broken digitizer. Take it to the apple store. If they won't help you, You can try to replace the part yourself, it is available on any auction website (iPhone 4G digitizer/LCD assembly). There is an iPhone 4G Repair service that can fix it for you, but if you're a little tech savy you should use an iPhone 4G repair guide that teaches you how to do the repair yourself.