They are OK and quite a good idea as a backup copy (but never as "storage")
I am currently have and am using a Free Agent Desk 500GB
External Hard drive with a speed of 7200.
I was thinking of purchasing the WD My Passport Hard Drive 250GB
which is only $29.99 at Target and was wondering how reliable they are compared to the Free Agent drives.
I know that it's has a slower speed but I like the fact that it's USB powered
vice A/C/ and is extremely small.
I'm just going to be using this as a backup for my MP3 files.
Also, if someone knows of another good USB powered hard drive
please let me know.

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