Ken Werner has written a nice guide to installing Fedora 11 on the PS3. (And I’ve added the link to the Linux distro page).
Inside Ken’s page is some details on installing and running demos from the recent “OpenCL Development Kit for Linux on Power”, which is something I’m now even more keen to try :)
(It seems a little odd that the only place that OpenCL SPE acceleration is mentioned is in one of the FAQs…)