|Nothing to worry to much. As you posted this question twice I copy/pasted my answer here:|
You may have accidentally activated the Zoom feature. To zoom out double tab your iPhone screen using 3 fingers. After this, if you don't want to use this zoom feature, connect your iPhone to a computer and open iTunes. When your device appears click on it. On the general tab go down to Options and click on Configure Universal Access... Click on Neither to disable the zoom. This is ONLY for iPhones 3GS and iPod Touch 3rd generation.