is there really anything good to do with them instead of letting them sit in a drawer full of other unused hard drives?

They all should be working still none of them are above 100 gigs though....

Buy some external hard drive cases off ebay and sell em

Sorry - have to disagree with that last post unless you are absolutely certain there is no deeply personal info (DPI) on them. There is a very active trade in old hard drives into West Africa (I know - I used to work there) where they are searched for DPI which is then used to raid bank accounts and the like.
Destroy them by taking the platters out and using them as cup stands.

I agree. I would never sell any of my HDD's. If you purchase an External Harddrive 'Enclosure', you can plug them into your existing PC and use them as a backup or extra storage

I agree. As albert and others say above. Make sure you erase them properly.

However, if you have nothing personal or important, might as well send them to me ^^.
Honestly, they don't serve any purpose, unless your short on space or want to back up stuff on them.

There are thousands of kids with nothing... donate the drives, find some old cases... and inspire some of these kids to learn something better than they now know... You don't need those drives and they do...
It will change your life for the better, and it will certainly change theirs.

Been trying to find places that recycle old computers and components but nothing really exists around here yet I do have several older systems lying around here all under 1ghz and working though my first computer a Cyrix II 300mhz system wasn't POSTing properly last time i tried it ...

Is it sad when you have like 30+ CD rom drives lying around?

The reason none of the recycle places exist any more is that people are taking out the hard drives before handing them over; this then makes refurbishment too expensive. Once again a dishonest minority have prevented the poor and needy from receiving a valuable benefit.
I stick by my rule - I never ever let old hard drives back on the market. Ever.

I was really thinking more like places that actually recycle the old boards etc like melt them down and what not and reuse the metals for new products

Thats another completely different can of worms - most of these recycling places are in the poorest and worst controlled countries (Brazil, Ghana, China, etc etc) where the chemicals used to leach out the metals like gold are actually poisoning the people who do it. Still, it might be marginally better than landfill.

I have actually found a few places that do it here in the US but they want money to do it which is not something i really have to spare currently

I am surprised that no one has mentioned electromagnets. One can be built from common household items that will do the job to a military grade of security. A simple google will produce many results.

Often tried, but seldom works as well as promised... and certainly not to a miltary grade of security (if there is one yet).. but not to Federal standards, for sure.
Have worked on many projects where this was attempted. They were all laughers.
Think about it. If this really worked, everybody would be doing it.
To remove them from circulation, use an electric drill and a good bit.
To make them re-usable, just reformat them a three times. Nobody knows how to recover from drives from which they do not know the source.

It has been proven many times that degaussers (magnetic systems) don't not work nearly often enough. Hard drives have such strong shielding that the magnetic oersteds (Oe) used to destroy the data can only achieve a high enough field intensity to destroy the read-write arm. Therefore, it's often possible to remove the platters, so the bad guys put them in new disk housing with a new read-write arm, and read the data that you thought you had destroyed.

The new disk shielding technologies have made degaussers unreliable at best.

Reformatting a disk can wipe out the data, but reformatting a disk is very time consuming. It can take hours to reformat one disk. And the system reformatting the disk needs to be operational. The Hard Disk Crusher can destroy a disk and the data on it in just seconds without the need of a peripheral PC or workstation.

True, that a very good technician can recover a formatted drive when he has special equipment... but when nobody knows the source of the drive, that effort is relatively futile.