Hm, that's cool.
http://www.theopencd.org/You could start your own "live opencd" project, with "live OOo/gaim/firefox" etc. on it. You could try opera too, but you'd need to get permission from them to redistribute it.
In school I have FF installed in my network folder and I can run it on all the computers. So, for just a few MB, you could copy the directory FF is installed to onto the CD. You could get some extensions and stuff in it too...
GAIM I also have installed on my folder on the network in school, but I have to set the library search path (LD_LIBRARY_PATH?) on each computer so it can find the GTK+/etc. libraries.
Programs after installation are usually bigger than the install files, so you mightn't get too much on them.