Wow, I can see picture files or videos taking a ton of room, but you have an 80GB program or is that work product of some kind?
I went so far back that I used to do cost accounting reports of hundreds of pages using a Durango D-Basic machine and two floppys.
http://www.old-computers.com/museum/computer.asp?st=1&c=939
I think I had a 512k disk for the program and another 512k disk for a year of reports. LOL
Some numbers about videos:
When that time comes, Pixar's render farm will have to go through another massive growth spurt. And so will its storage space, which Whitehill estimates already exceeds five petabytes, or 5.4 million gigs.
Science experiments, like LHC, are producing gigabytes of data per second. Astronomy can also give you more data than you can handle.
The most likely demand for space at home comes from backups. This includes backups of your computer storage, and backups of your DVDs (in case they get scratched.) It is very appealing to have an endless history of your filesystem that goes back for years. You can then access any file that you used to have on the box, even if you deleted it a year ago and only now (at tax time) realized what have happened.