At this time am only interested in booting a Mac with tinycore from a USB stick, whether there is a internal drive installed on the mac itself is of no importance. To make file editing easier I sometimes connect a drive with OSX 10.7.4 installed on it. Having said that, it's only a question of time before all new pc's use EFI, I would say at least withing two years.
Strange thing, one day I accidentally grabbed the wrong drive and connected it to the macbook, on start it booted up into Windows 7 immediately without any issue on the macbook, next time I looked the system was loading new drivers (the drive had been temporarily removed from a windows pc.. ) lol
Anyhow, back to core.. is there a way to verify that linux has been compiled with the efi flag ?
As an experiment, I installed rEFIt to a USBstick with tc and elilo.efi, which at least loads vmlinuz and core.gz but crashes then promptly reboots before I can figure out why.
update, having better success with vmlinuz64 & core64.gz but still no cigar