There are more than 113,000 files in my top-level photo directory (which thankfully now resides on a RAID 5 box in the closet).
Data loss terrifies me, and so I have finally have started the arduous process of archiving everything onto DVD-R. I do own a 33GB tape drive, but at $60 or more per tape, I'd rather use 7 DVDs (less than $5) to store the same amount of information.
In the immediate future dual-layer writeable DVDs will be available in quantity and presumably will begin to fall in price, and in the longer term Blu-Ray will up the storage capacities of a single disc to 25/50GB. But at some point you have to commit to a media format and start backing up.
The problem is that the rate at which my data needs is growing is surpassing the rate at which cost-effective removeable media capacities are growing. For example, it would be great to be able to back up my life onto 20 or so discs, but currently I would probably require 100 discs or more. So instead, I tend to keep my data on multiple drives in separate machines, reserving the risk of catastrophic data loss for acts of God (and more recently, the risk of viruses brought behind the firewall by roommates). That's not good enough, I don't think. I need to have copies stored off-site -- hence, the DVD-burning binge that I'm going through right now.
I've thought about rsyncing my data to a remote server, but even at an upload speed of 100 KB/sec, 500GB would take roughly 57 days to upload. I suppose I could walk into a CoLo with a server already seeded with the data, banking on the fact that incremental updates won't take up as much bandwidth...
Also, I'm amazed at how many of my friends simply do not back their data up. As much as possible, I've been forcing loved-ones to use mirrored hard disks in their desktop machines, which will at least account for the possibility of drive failure.
Blah blah blah. Boring content today. But it's what is on my mind. :)