Irish stand-up whirlwind Tommy Tiernan, who had a spot on Letterman in June, is preparing for shows at the Mercury Theater (3745 North Southport) September 28- 30.

"Tommy Tiernan Live in Chicago" will be on DVD and cable next year. Thursday and Friday's shows are at 8 p.m., and Saturday he'll be onstage at 7 and 10 p.m.

Tiernan is a huge favorite on the international festival circuit, employing the kind of effusive irreverence that so oftens seems to spring from a traditional Catholic childhood, as he comments on sex, religion, drinking, and Irish as well as American culture.

Clips can be found here, including this one, from the Montreal Comedy Festival, where Tommy expounds on his theory that Christmas was meant to be a commercial enterprise from the very beginning: