"Are there any special printers which can print on them.
Yes, there are ... for example the MantraJet 1050 CD/DVD auto-printer
Standard HP cartridges True photo print quality 50 or 100 disc capacity Use any graphics application. There is no need for any special duplication software.Just enter how many copies you need in the print dialog box of any label design software and come back when all discs are printed Ultra-high speed loading mechanism Excellent service-ability Powerful fan to minimize the ink contamination Smallest footprint in the industry - perfect for live event recording
Or the DYMO DiscPainter
TEAC and Casio offer black&white thermal transfer disk printers which are cheaper ($50-100)."