Does anyone know of a way to send data on a CD such that it is only accessible (with password) before a certain date?

I'm looking for something like this for work. We need to send some documents to review, but they are prioprietary and the reviewers need only have access temporarily. I've heard of something like this, but after 20 minutes of Google searching, I can't find any free solutions. The best I came up with was this http://www.encryptx.com/small_business_feature_comparison.php. Since it's for work, I don't mind paying, but free is always better...

I know that there are always workarounds (hacks/cracks) for this stuff and nothing is foolproof. I just want to defend against casual theft if the CD was not destroyed after their review.

I have no background to this and it's just a thought but....

Can't you send a disk write protected so it can't be copied with a password. Then also ask to have the cd sent back by a specified date and make them sign a contract. Thus if all specified rules aren't complied with you can bring legal hell down on them.

u can try truecrypt. but it doesn't have the self destruct function