Continuing the stream-lined presentation of cutdown D20 rules, here's all you need to include psionics, the powers of the mind, to your game.
It starts off with five new races - presumably they are capable of psionics although this isn't stated, nor anything about the races we already have. Apparently your character becomes a psionic by choosing one of the specialist psionic classes which are the next thing to be detailed. These are the Psion (who concentrates on his mental powers), the Psychic Warrior (who combines mental and physical prowess) and the Wilder (who is, well, a bit wild and uncontrolled!).
Then there's a new skill: concentration. Only psionics are capable of it, and it is used for focussing your powers as well as for rising above mundane distractions to get on with something else. Then we move on to the psychic powers themselves. They use a power point system, and there are lists akin to spell lists of what is possible and how much they cost to employ.
Finally, there are some psionic monsters too, which can employ various powers against characters (who need not, of course, be psionically active themselves!). Indeed it can be quite entertaining not to allow psionics to PCs, but have some adversaries using these - to your players - strange and exotic abilities. (Or am I just a nasty GM?)
A large amount of 'crunch' concisely presented and straightforward to use.