best small size export format for mobile

Hi guys,

What's the best settings for exporting 5 minute clips for mobile devises?

Obviously, the screen dimensions will be a lot smaller, maybe Ipad size at best?

I currently have a 5 minute clip that is 168MB after selecting H264 and 720HD mobile devise.I'd like to get the overall size down to something smaller that will still look good on a mobile devise.

Cheers,