How-to create Firefox Portable Live for Mac OS X and Linux?

Hi *,

Firefox Portable Live ist interesting, but:
Are there any instructions ...

... on how-to create a Firefox Portable Live "from scratch" (i.e. by downloading the regular FF distribution from mozilla.com)?
... doing this for both the Mac OS X and Linux version of FF?
... where to find the Launcher source in the FF source provided by portableapps.com (so to somehow adopt it to Mac OS X and Linux)?

Background: I want to put both Firefox executable and profile folder on a read-only USB stick or CDR (for Mac OS X and Linux).

What I have done so far: I have a running FF (with profile folder) on a read-write USB stick, but as soon as I turn the switch to read-only, FF starts complaining upon start-up ("... bla ... already running ... bla ...").

Any hints on how to fix this?