WARNING: Side Issue.

I've thought about using the type of drives you discuss as a near real-time backup/dr system: Running a SQL server on a virtual windows box whose os image is stored on a cheap external ide drive that's running somewhere offsite. (my main db is in the 700 gb range, so something like ~1 tb.) Then use SQL replication to keep that server in sync with the real thing. It seems to me that something like a cable modem (~6 mb downstream) might just provide enough bandwidth to do ~hourly replication. If it works, you get very near real time backup, and you even have a hot spare sql server, albeit a slow one.

The idea is very appealing to me.

What am I missing?

Bob