On iOS 5.1.1 if I "erase all content and settings" will I need to plug into iTunes?

Long story short, I need to erase an iPhone I'm using and I'm in a different state than where my computer with iTunes is. I just want to know if I do erase the iPhone, upon restart will it tell me I have to plug into iTunes? Or hasn't that been omitted since the big feature of iOS5 is you don't need a computer right?

No it's not jailbroken. So to confirm, if I erase the iPhone 3GS I will not have to plug into iTunes. Right?

I just can't have this thing fail because I'm out of town until Friday but I have 0 bytes of memory left and need to free up space, but at the same time need it this week for work.