My iPhone 4 started System Restore on its own

This afternoon my iTunes suddenly stopped recognizing my iPhone 4 (on iOS 5) and started a System Restore over Wi-Fi on its own. I was afraid it would lose connection so I connected the phone via hard wire about 10 minutes in. It's been trying to restore itself for about 5 hours and the "time remaining" is growing rather than decreasing. When I left the house this afternoon it said 15 minutes, now it reads 4 hours. My phone only reads "Restore in Progress." I'm not sure what to do now. I don't want to disconnect and risk making things worse. Should I just let it go overnight ond hope for the best or is there something else I can do? Any suggestions? Thanks.

Have you hacked any setting on your iPhone? If not, try reseting your iPhone (this does not remove data like a restore to factory settings will do): Press and hold down the Sleep/Wake button and Home button simultaneously for at least 10 seconds; the screen will clear out and then the Apple logo will appear on the black background. When the logo appears it means that reset is done. Cheers, Lee