Converting Video to a .GIF

I know that photo booth offers the export option and you can make a .gif from that, however it is very short. I also heard that Quicktime Pro offers a option similar but for a longer period of time.
I was wondering if there is any truth to that, or if there is another application that gives you that option. I just want to make about 5 second .gif's from videos that are not just from photo booth.
Thank you.