Holt Renfrew is leveraging Toronto-based Grassroots Advertising’s Window FX by installing touchscreens at its Toronto Bloor St. location as part of the high-end retailer’s new Contemporary Correspondent Search contest which runs through Aug. 4. The storefront screens invite passersby to vote for one of two fashion blogger finalists, pitted against each other in Toronto, Montreal and Vancouver respectively in a series of challenges, with the winner receiving a $1,000 Holt Renfrew wardrobe, a Sony VAIO notebook PC, and the chance to get a behind the scenes look at regional fashion events and blog about them. Grassroots Advertising’s latest offering features a number of interactivity options through infrared sensors that respond based on the approach of pedestrians, such as motion activation, a touchscreen and SMS interactivity with the window advertising via cell phone texting. (The technology works by placing a special film in the window, the most common being 3M Vikuiti, and projecting onto it with a high resolution projector.) Holt…