ANONYMOUS  Many of these items, like clearing your cache/history, can be done manually, one-at-a-time on each application. However, those items are NOT securely deleted. A simple program can be downloaded that will allow you to view the contents of those items you thought were deleted.

With MacPrivacy, all deletes happen securely. So all history, cache, etc, are cleared with a US Department of Defence compliant 7 pass wipe. This includes your browser history, cache, etc, and files that you can manually specify.

MacPrivacy also makes it much more convenient, so you do everything with just 1 click :)  
(Version 1.2)