In an episode in the first season where Emily gives loralei DSL (for her interenet), Loralei comes home to find some one installing it.. Loralei asks what his name is and he adresses himself as Mick.. But really Mick is Kirk in the later episodes..
According to IMDB.com: Sean Gunn, who plays Kirk, made his first appearance in episode 1.2 ("The Lorelais' First Day at Chilton"), but not as Kirk. His character was named "Mick" and he was installing a DSL server at the Lorelais' home that was ordered by Emily.