New York-based GPShopper, a startup focusing on product search for mobile, has raised an unspecified first round investment from investment bank Allen & Co. The company aggregates real-time retail inventory info, delivering it to shoppers based on zip code or GPS information. The plan is for retailers to pay for inclusion, with GPShopper receiving a cut every time a user clicks on a product link. In June, it launched Slifter, a mobile shopping service, through Sprint (NYSE: S) Nextel’s network. Release (.pdf)