Video needs to be rotated

[alra111]

I uploaded a video I shot on my iPhone 3G S to YouTube and the video came out rotated. It needs to be rotated 90˚ CCW. Why did this happen, how can I avoid it next time, and is there a way to rotate the video I took so that I can re-upload it?

Thanks for any help you may be able to provide!

Alra111

 

[simbalala]

I knew this had been asked before.

Sideways Video