OK I ama mom and I need help concering an Ipod Nano - tell me please what the difference is between 4GB & 8GB?

(My Original Blog Post: http://www.latesttrendsguide.com/?p=4018)

My daughter is 11 and this is expensive but its all she wants for christmas - is this one better than the Ipod shuffle? I know that the Nano does the videos and thats really what she wants/

Thanks in advance for your help