What do I do with old unwanted external hard drives?

[Anne Sh]

Like a number of us I have been a serious backuper. As the result I have accumulated a number of external hard drives over the years. Some are 350gbs and less.
How and where do I dispose of them safely both environmentally and to ensure that my backed up data is destroyed.

I am sure that there are good ways to dispose of these drives rather than just send them to land fill.

[ricktas]

Donate them to local charities, schools etc. That is what I do

[I @ M]

Ooooh what fun.

Seriously, pull it apart completely and donate the screws / bolts / nuts to a handy man, make sure all the metal parts go to a recycling bin and then delicately smash the platters in the drive itself.

Problem solvered and fun had at the same time.

The only part I don't know about ( tech challenged ) is if there is any retained voltage in the drive so caution may need to be exercised around the electrical bits.

[Cyza]

I'd imagine alot of people would quite happily take them of your hands, assuming you have deleted all the data completely, you'd be doing some one a favour and saving yourself the effort of pulling it apart or driving somewhere to recycle/destroy it.

[arthurking83]

Both donation of the device and the disassembly of it are good options to consider.

If you are into macro photography, the internals make for good/interesting/shiny/difficult subject matter.
If you are of the extremely charitable type, I'm sure a family member friend or local charity/op shop may find it useful too.

Use a secure drive wiper to make it hard for anyone to access the data easily.(CCCleaner is good for this).

[photomike666]

Format them, or download a program that cleans the drive so nothing is recoverable, then sell them on eBay.

[Kym]

The only part I don't know about ( tech challenged ) is if there is any retained voltage in the drive so caution may need to be exercised around the electrical bits.

Non issue. Just some small electrolytic caps that will be discharged after ~10 seconds.
You can get free diskwipe software.
http://www.diskwipe.org/

[Xenedis]

I disposed of a number of disks a few months ago. Most of them were 2.5" (laptop) hard disks.

I disassembled them, removed the platters and destroyed them.

The platters in laptop hard disks are ceramic and therefore very brittle, and will shatter into hundreds of fragments when struck.

The one 3.5" 40GB HDD I had wasn't so easy to destroy, but I gave the platter a good hammering (literally).

[Anne Sh]

Thanks everyone for your great ideas...

I have a mac so will reformatting them through disk utility be enough or do I need to download some of the software that has been suggested by Richard or Photomike666 and wipe them with that as well?

[Anne Sh]

Thanks Richard that link was extremely helpful...to confirm that I have erased things properly.