In what appears to be a guerrilla marketing effort, chalk-like drawings of children holding or playing with large Sony PSP consoles have been popping up in a number of cities, including New York, Philadelphia, Chicago and San Francisco, according to gamer site joystiq.com. And the Wooster Collective, a New York site dedicated to street art, has posted images currently appearing on Seventh Avenue scaffolding on its site, in addition to the one pictured here from Philly. Assuming this is an ad campaign, and not social commentary, it’s the work of TBWAChiatDay, which handles domestic advertising for Sony PlayStation. But while the Wooster Collective seems to like the effort, people commenting at joystiq.com gave it mixed reviews. One even claimed that he saw several stickers from the campaign in the bathroom of a bar he apparently works at—and complained that it took 45 minutes to peel them off the wall.