Chrono Cross Characters
Here is information on how to get the characters in Chrono Cross.  They are not all here yet, it will take 2 or more replays of the game to get them all!  However, I'm listing those which I have got so far.  They are listed in alphabetical order.
Serge
Serge is the main character of the game.  Obviously, you get him by default.
Kid
Kid will join Serge if you accept her request after the battle with Karsh, Solt and Peppor on Cape Howl.
Korcha
When you go to Termina, check out the market stalls.  Talk to all the sellers, and Korcha will annoy one of them, then run off.  Now go right past Lisa's weapon shop and down to the beach.  Talk to Korcha.  He will offer to give you a ride in his boat if you get someone who knows the way.  (Guile knows the way).  He will join your party once you get back to Termina after the boat trip.
Guile
Guile is found in the Termina bar.  Talk to the man cleaning the statue in Termina, then agree with Kid to go to the Viper Mansion.  Then go talk to Guile and tell him you will help him.
Greco
When you are at Termina after going to the Viper Mansion, go to the shrines and watch Greco and Riddel at the shrines.  Then, follow Greco into the building, and talk to him.
Razzly
At the Hydra Marshes in 'Another World' fight the Beebas (near the Records of Fate) and you will be given the Beeba Flute.  Now continue to the left and you will reach a wide open space.  Use the Beeba Flute and fight the Wingepede.  After the battle walk to the middle of the space and the ground will break open and you will fall down into the hole containing a nasty monster.  Walk to the SouthEast conrner, and examine the cage.  Fight the Pentapus, then examine the cage again.
Pip
In the Viper Mansion, when you are in the laboratory, open Pip's cage.  He is in the SouthWest corner.  When you are back on the world map and you have a boat, go to the East end of the continent that has Arni Village, Hydra Marshes etc, and enter the fog.  You will be on a ghost ship.  In one of the rooms there will be a small white animal  (it looks like a headless chicken!!!).  Talk to it and keep following it.  Eventually it will talk to you and join your party.
Poshul
Poshul is in the yard to the West of the fish sellers in Serge's world.  Give him the Heckran Bone and he will join your party.  If you get Leena to join your party, she will bring Poshul with her and you will keep the Heckran Bone.
Leena
Leena is found on the pier of Arni Village.  She will join Serge if he is alone.
More to be added!