What do you guys do with older smaller drives?

I bought a 4TB drive to replace my old drives, and I'm going to have a bunch of old drives lying around and was wondering what to do with them, they are:

1TB Western Digital

1TB Seagate

1.5TB Seagate

500GB Samsung

300GB Maxtor

150GB 10,000rpm WD raptor

Alltogether they would make up roughly 4.45TB. What would you guys do? I'm thinking of setting up a JBOD linear array and use these drives as one large backup disk with an older computer setup that I have (backup fileserver), I'll keep it turned off whenever I'm not running a backup to keep the drives from wearing down... that way whenever I come across another disk I can add it to the others and expand the storage....

Is this a good idea? What do you guys do with your old small drives?

As long as it is a backup of a backup and you aren't putting all your eggs on drives that are almost all certainly out of warranty I don't see any reason not to. I use mine if my test virtual server.

I wouldn't bother with anything under 1 TB and I wouldn't trust critical data to old drives.