Alyson Hannigan has been signed to appear in a guest role on hit American sitcom That '70s Show.

The former Willow Rosenberg will, according to Variety, appear in at least two episodes of the hit comedy on the Fox network.

Familiar to us from her seven years in Sunnydale, Hannigan probably has a stronger Hollywood profile than any of her former Buffy co-stars, thanks to the $100-million-plus box-office of the third American Pie movie, American Wedding.

That '70s Show, based around the lives of Midwestern teenagers growing up in - surprisingly enough - the 1970s, began in 1998 and starts its sixth season on Fox on October 29th. Insomniac British viewers can currently catch some first season episodes in the pre-dawn hours on Sundays, on channel Five.