[PLUG] Hot swapping physical /home partitions - Possible? Practical alternative?

[Richard Owlett]

Yes, my question is as strange as the subject line ;o>

The hard drive on my old desktop is dying.
I've copied the /home partition to a flash drive.
I've a laptop with 3 separate configurations of Debian installed.
Each is optimized for different goals.
The fstab file of each references the same physical partition as /home.

Ideally I want the most recent install to be able to "hot swap" between 
the the two "home partitions".

Alternatively would it be possible to chose between 2 different fstab 
files at boot time?

Is there a sane alternative?

TIA