It's stunning how memory prices have dropped. It wasn't so long ago that I spent about $100 on a 320mb (that's Mega- not Giga-) Microdrive to put into my PDA to record class lectures. For those who don't remember, these were 1" hard drives that fit into a CompactFlash II slot. Being mechanical (the motor was amazing), it drew quite a bit of power, draining my Sony Clie NX80 PDA in about 20 mins.
This offers 20x the memory at half the price, at much lower power consumption and higher reliability.
Even the concept of non-volatile Flash memory boggles my mind. In my days, the only thing that came close was very cumbersome and slow EPROM, which used UV light to erase the contents. And home users can't select what to erase; you have to re-format the entire thing. You can't dynamically use it like RAM.
One of my favorite Seinfeld episodes dealt with George desperately trying to keep his Frogger high score while moving the game console. Once unplugged, everything gets erased. Flash memory, which needs no electricity to maintain contents, was just a few years away.