Hm...I think, with Office 2007, and RMS, we may stop the reader to copy the content only. But cannot stop the reader to take screen shot. Microsoft MVP, Microsoft Community Star(TW & HK), MCT, MCSD, MCAD, MCSE+I, MCDBA, MCDST, MCSA
You can set the document have password and it can be read only. If you are using Office 2007, you may save it as PDF and find some way to do a digital signature on this PDF file. However, we cannot set a document have 30 days "trial"