Personal Brain on Palm is an initiative by two French guys to emulate the PersonalBrain program (a.k.a. TheBrain) on a PalmTop.
Unfortunately, it seems just to have broken the technical barrier of picking a .brn (TheBrain file) and converting it in a .pdb (Palm database file). The interface isn't intuitive like the program it tries to simulate.
Maybe because of all the patents hanging on TheBrain.
See also ThoughtStream