Burning Data+Audio Disc It's been a long time since I've ever had to burn something that isn't just a set of data, or an ISO (via Disk Utility), but now I have to burn a Multi-Session disc.

Are there easy ways of burning a data ISO first, followed by MP3s (as standard Redbook Audio tracks), other than paying $80 for Roxio's Toast burning software?
While these instructions on Apple's website (Apple support doc) are for OS X 10.4, they still work in Snow Leopard.  It has been a very long time since I had to do a multi-session CD, but I remember doing this way or in a very similar way. It's worth a try and a CD-R costs a lot less that Toast.