dont know if its old news or not but i just came across a program called Mode2 CD Maker.
quoted from cdmediaworld.com
this chart shows about how much you can store on diferent size media. according to this, you can store almost a gig onto a 99 minute cd
Mode2 CD Maker is a small DOS based tool created by DeXT which is able to create a CD/XA Mode2/Form2 ISO Bridge type CD. This CD format is similar to VCD but it can use any content (not just MPEG files). This it is possible to create DATA CD's which can store about 14% more data on a CD-R media.
linkage: scroll down to news from may27th
Mode/Media CD-R74 CD-R80 CD-R90 CD-R99
Mode 1 650 MB 703 MB 791 MB 870 MB
Mode 2 738 MB 798 MB 897 MB 987 MB