Been playing the card game "war" with the youngsters (teaches hand dexterity and maths...) with a Star Wars deck and started to think about Boba Fett; just where did he come in? Found this video [dodgy -ed.] and comments below after a bit of searching.
Fett was one of the first new characters to be designed for The Empire Strikes Back. He can trace his origins to rejected Darth Vader concepts that once had the Dark Lord as a rogue bounty hunter. Concept artists Ralph McQuarrie and Joe Johnston were most responsible for Fett's design. He first appeared in an 11-minute animated segment of the lamentable "Star Wars Holiday Special" television broadcast in 1978. Fett had another pre-Empire appearance in the daily newspaper strip story arc entitled "The Frozen World of Ota." Given that Fett and Skywalker meet for the first time in both stories, and Luke unwittingly befriends the bounty hunter each time, one or both of these tales is probably apocryphal.
Fett was the first new action figure for The Empire Strikes Back line of toys. He was originally available as a mail-away offer; kids would send in the appropriate proofs-of-purchase and Kenner would send the toy out. The original mail-away offers stated that Fett would feature a rocket-firing backpack, but safety issues dictated that the toy was released with the rocket glued in.
Fett's big-screen appearance had actor Jeremy Bulloch behind the mask, though the character was coldly voiced by Jason Wingreen. For his return appearance in the Star Wars Trilogy: Special Edition, various Industrial Light & Magic artists wore the armor.
-via Jedi Council forum