This had been bugging me for some time so a little research on the web helped me to come up with this:
As you can see we should be reaching the Terabyte mark somewhere between '07 and '08 and almost 5 Terabytes by 2010! To put it in perspective that's 125 times the size of the current drive on my laptop... What will we all be doing with this space - any thoughts?
Well, I for one will look forward to upgrading the lame 40GB on my TiVo... Let's work that out: 40GB currently provides me with 80hrs. of recording time so 5TB is a whopping 10,000 hours of programming! Thinking about it that's probably about quadruple the total amount of time that I've 'invested' watching movies (not TV programs) since I was born... Furthermore, assuming that you record/watch 4 hours of programming per day then you could record almost 7 years worth before you found the need to delete anything (and that's before considering any further advances in compression technology). By then you'd probably need to have Google installed on your TiVo just to find your recorded programs...
The chart above is based on a study which you can find here.
Now that you have an idea of when you'll be able to afford a Terabyte you may want to find out what a Yottabyte is at Berkeley's 'Data Powers of Ten'
Not to be missed is of course the Eames Office authors of the fantastic 'The Powers of Ten' film and book.
If you've never seen the film or read the book then check out an interactive slide show with all the images contained in the book here.