External hard drives definitely have their place
for doing backups. But most people don't realize that inexpensive
consumer-grade hard drives fail just as frequently as the hard drives
built into their computers. And, if they are right next to your
computer, they will typically share its fate in the event of theft,
fire, power surges, etc. Now here's another thing to worry about:
IDG news service reported last month that several
models of Seagate's popular Barracuda and DiamondMax external hard
drives have faulty firmware that is causing the hard drives to "freeze"
under certain conditions. The article that I read refers to this
condition as "bricked," a term I hadn't run across before but which is
amusingly descriptive of what you can do with a frozen hard drive.
Seagate is a great company, so I'm sure they'll fix this problem, but
there's only so much you can do when there is a single point of failure.
I've said in the past, any single hard drive is going to be much more
vulnerable to data loss than the RAID arrays that Carbonite uses (which
are 36,000,000 times more reliable than a single hard drive because of
redundancy). So while external drives are a good and inexpensive way to
store big files such as ripped movies or TV shows, I wouldn't consider
them safe enough to store my irreplaceable photos or financial records.