Excerpt From Backstage West March 29th 2001 FUNNY BUSINESS By Jamie Painter Young      If you're a comedian, getting invited to perform at the US Comedy Arts Festival in Aspen is somewhat equivalent to being an independent filmmaker invited to showcase your film at Sundance. Aspen is the place to be seen in the United States by agents, managers, comedy bookers, network bigwigs, and production company execs who congregate each winter in the ritzy, Colorado ski village to see what's being touted as the top comedic acts from around the country, as well as a few imports from such faraway places as Great Britain.      Though most performers who've made the treck to the five day festival (which wound up its seventh annual event a few weeks ago) will tell you they get much out of the experience, the truth is that most of them do not walk away from Aspen with lucrative development deals in their pockets.      As standup Jim Gaffigan, who returned for his second stint at the festival, said, "I think Aspen is a great showcase, but I think sometimes people have this notion that they are going to walk away with gigantic deals. I think Aspen is more of a debutante ball, and I think there are rarely Cinderella stories, and most of the time when people hear these Cinderella stories, they have actually happened over along time."     Gaffigan is a good example of one of the stories that sounds like an overnight success but in reality involved over a decade of rejection before luck struck.     Two days before heading to Aspen two years ago, he made an oral agreement with David Letterman's company, Worldwide Pants to star in a proposed series, "Welcome to New York," for CBS. While the timing was great, Gaffigan pointed out that he had spent nine frustrating years struggling to get noticed as a standup, and it was not until a few months before Aspen that his career began to gain momentum.