Be aware, Sony has removed the "other OS" function in the latest firmware release.
I suppose this means if you had previously installed linux, you can no longer access it after you upgrade your firmware. This was version 3.21 released April 1010.
This also means your PS3 can no longer run boinc, and that you paid for a feature you can no longer use after upgrade. You cannot go backwards.
If you do not upgrade, then other new features become usless as the old firmware will not support them.
This is a double edged sword, you can't have both.
There are 3 lawsuits being filed against Sony over this.
See this article, http://ps3.ign.com/articles/108/1088481p1.html
it has links to all the lawsuits and other material relating to this.
Please share this news with other PS3 owners and on forums on projects that have a PS3 application.