Erase Free Space on Mac OS X

In order to erase all free space on Mac OS X, use Disk Utility.

Secure Empty Trash on Mac OS X

Right-click on the Trash icon in the dock, hold down the command key, and then select "Secure Empty Trash". If you want to always securely delete files, you can enable this setting by going to Finder > Preferences and then selecting "Empty Trash Securely" under the Advanced tab.

Fujitsu ScanSnap S510 drivers for Mac

You can now use your Fujitsu ScanSnap S510 on a Macintosh.  Someone figured out that the S1500M drivers for Mac OSX will work with an S510:

https://discussions.apple.com/thread/4391068?tstart=0