While trying to upgrade my iPhone 3G from iOS 4.0 to iOS 4.0.1 it simply got stuck on “waiting for iphone” step on iTunes for 
a very long time. Quite frustrating ! huh!
The solution is simple, just RESTART your computer and it should fix it.
Other people proposed like taking out sim card, using other sim port or other computer or turning off the apple mobile device service (which is logical to the restart process too).
Hopefully now when you retry the procedure of upgrading / restoring your iPhone firmware it will not stuck on the waiting for the iPhone step on iTunes.
I just waited a very long time, and it actually started.
almost how long? coz i waited for like 15+ minutes, but restarting my system solved it instantly
Wow this is a great resource.. I’m enjoying it.. good article
you’re welcome to browse through the blog and read many other related articles
15 minutes is not along time people and there i want it now attitude i was updating mine and know it got stuck while updating software now iphone is frozen at the apple logo with bar under it been that way for about 7 hours wont connect to computer even though it wasnt taking out of the computer so my phone is screwed
did you try restoring your iPhone os?