I remember the first time I ever heard the term gigabyte. Actually, I didn't hear it, I worked it out myself. It was the early '90s, and my friend Paul had just ordered a new hard drive for his 486. I remember how excited he was to get a 100MB drive, which was easily twice as big as the one he had at the time. I was astounded and said, "How big do they go now?"
"Next year, they'll hit 1,000 megabytes," Paul said.
I was even more awe struck. I said, "1,000 megabytes. That would be--1 gigabyte?"
Paul just looked at me and said, reverently, "Yes."
Now, of course, you can fit 4GB onto a microSD card the size of your thumbnail. But the above image, from ToxicJunction, really shows how far data storage has come in 20 years: it's 1GB in 1988 and 1GB in 2008.