Let me clearify things for you.

• Ratchet and Clank (1) - PS2 (Insomniac Games)
• Ratchet and Clank: Going CommandoLocked and Loaded(2) - PS2 (Insomniac Games)
• Ratchet and Clank: Up Your Arsenal (3) - PS2 (Online Broadband) (Insomniac Games)
• Ratchet: Deadlocked/Gladiator (4) - PS2 (Online Broadband) (Insomniac Games)
• Ratchet and Clank: Going Mobile/Clone Home(?) - Mobile Phone (Sony Computer Entertainment)
• Ratchet and Clank: Size Matters (5) - PSP (Online Broadband) (High Impact Games)
• Ratchet and Clank Future: Tools of Destruction (6) - PS3 (Insomniac Games)
• Secret Agent Clank (5/6) - PSP (High Impact Games) (Coming This Summer!)

Sony Computer Entertainment will also be porting Ratchet and Clank: Size Matters, originally designed for the PlayStation Portable by High Impact Games, over to the PlayStation 2 on March 11th, 2008. I know that a lot of people have been saying that it's just a rumor, but I got an E-mail the other day from Sony Computer Entertainment (The PlayStation Underground Newsletter) giving the official word of it infact being ported to the PlayStation 2.

Cheers, S4P