Most pre-draft speculation had the Lions going with Texas cornerback Quentin Jammer.
Harrington, however, was considered by many scouts just as outstanding a prospect as Fresno State quarterback David Carr, who was made the No. 1 pick in the draft by the Houston Texans.
Like Carr, Harrington has a quick release and is a classic pocket passer.
"I was thinking Detroit would pick somebody else and all of a sudden I got a call from the Lions," said Harrington. "I'm thrilled."
Harrington's eventual destination was one of the big mysteries of the draft which some expecting him to not even be picked among the top 10.
He finished his career with 512 completions on 928 attempts for 6,911 yards, 59 touchdowns and only 23 interceptions in 33 games.
He added 210 yards and 18 scores on 145 carries. His 7,121 yards in total offense ranked third in school history.