Sorry for the double post, but edits are inferior when it's something you need people in the campaign to see
Tomorrow, at 12:30 PM EDT (I think that is 4:30 GMT) I'll be running a probably short introductory session on Psionics, Tome of Battle, and/or Incarnum. Feel free to show up even if you won't be using one of the systems or if you won't be in the campaign. I'll probably do an Level 5 practice scenario or two.
If you are planning on possibly attending, let me know here, and include which of the three you'd like to know more about. Here are a rundown of the systems and a brief description of the classes.
Incarnum runs on characters who shape soulmelds, which are daily constant magical effects. At higher levels these can be bound to chakras (magical item slots) for increased effect. All soulmelds (and some feats) can be invested with Essentia to increase potency
-Incarnates have the strongest soulshaping progression, gain access to all chakras, and the most essentia and soulmelds. They have fewer non-soulshaping features, though. They must have exactly one neutral component to their alignment.
-Soulborn have the weakest soulshaping progression, don't get the heart and soul chakras, and have the most non-soulshaping power. They require an extreme (no neutral components) alignment.
-Totemists have less soulshaping than the incarnates, don't get the soul chakra, get a special totem chakra, and incorporate themes of magical beasts in their abilities. They have no alignment restrictions.
Psionics involves power points, rather than spell slots, expended to use powers. Manifesters can augment their powers with more power points to increase potency, and gain the ability to enter a "psionic focus", which can be expended to power some feats, or kept for bonuses. There are some more classes in Complete Psionic, but:
-Psions are the barebones class. They tie with the Wilder for most power points, have the most powers known, and can gain a psicrystal which seems suspiciously like a familiar
-Psychic Warriors are something of a cross between a fighter and a psion; they have a moderate attack bonus, fewer powers, and a middling hit die.
-Soulknives don't actually manifest powers; instead, they use a weapon of psionic energy called a mind blade, which gains potency as the soulknife increases in level
-Wilders are the Sorcerer to the Psion's Wizard. They get a much smaller known power list, but get the ability to increase potency beyond what most manifesters are capable of.
The Tome of Battle, or Book of Nine Swords, is a major buff to melee characters, which seem a little lacking otherwise. Initiators can initiate maneuvers, which are either strikes, counters, or boosts. They can also enter special stances, which further increase power. Feel free to read the web enhancement I linked earlier to look at the maneuvers.
-Crusaders are heavy-combat fighters. They only get three disciplines to choose maneuvers from (Stone Dragon, White Raven, and Devoted Spirit), and have incredible ability to take a hit. Fluff-wise, they are similar to paladins, but without the severe alignment restrictions
-Swordsages are the lightweights of the ToB, and are maneuverable, fast, and deadly. They can be played as Rogues, Rangers, or, with the unarmed variant, Monks. They gain several disciplines (Desert Wind, Diamond Mind, Setting Sun, Shadow Hand, Stone Dragon, and Tiger Claw) and thus a crazy potential for variety.
-Warblades are a potent fighter-like class. Their lack of heavy armor is made up for by their other combat bonuses. They get five disciplines (Diamond Mind, Iron Heart, Stone Dragon, Tiger Claw, and White Raven), and all sorts of other things. Of special note is their capstone ability, which allows them to take two stances at once