As you may have seen on some websites, the Doom9 people have created a neat trick of storing more data to a regular CD-R. The trick is to store data inside a container multimedia file and then write file to the CD-R with Mode 2. The Mode 2 is used for example by the Video CD standard it has a weaker error protection coding so that more space is available for the actual data. The penalty of this process is that the written data is more vulnerable to disc damage such as dirt & scratches. This can be at least partially out worked by implementing some extra error correction coding to the container file. The 800 meg storage capacity might come very handy for writing large Divx movies to a CD-R with a writer that doesn't support 90/99 minute CD-R media.
The people at Doom9 are now calling this new CD format as XCD and they have some experimental software available for testing purposes. The XCD is NOT ready for daily use yet, but I am sure that the developers appreciate feedback, so go ahead geeks.