OT: Best way to destroy used CD-R's

[Dwayne Bradley]

I know that this is a little off topic, but I thought that this group 
should have plenty of experience with this.

What is the best way to destroy used CD-R's?  I have several that have 
personal backup data which is very old that I no longer need and I do 
not want to just throw them in the trash with this data still 
accessible.  What does everyone think?

Thanks in advance for all of the input.

Dwayne