Future of storage media

My dad and I have this arguement:

I say that before long, cell phones will encompass nearly all handheld devices into one device, and use a hard drive to store everything in. (A mini hard drive, ala iPod.)

He argues that before cell phones become that advanced, flash memory will also advance to the point where hard drives just aren't needed as a storage medium. He says that flash memory will grow to several gigabytes in size, and since flash memory has no moving parts and is faster, THere will be no reason to include hard drives.

Which situation is more likely to happen?

I wonder how useful optical computers will become. Generally, there seems to be an inverse relationship between distances and the usefulness of light. Ie, compare fibre optics vs all other technologies to DVD vs all other technologies. The smaller you go, the more trouble and less use it becomes.

Maybe in a very long time...