There was a flurry of rumors over the weekend that Google would launch a social networking service called Google Circles at SxSW. The company finally denied those rumors, said such an event would not happen, but did not deny that the service would eventually be launched. Now comes word that it will happen at the Google I/O conference in May. The idea of Circles, as we’ve been hearing about it, is to take advantage of search capabilities and let you create a more nuanced approach to your web presence. Sounds vague? Yeah, well, sorry. They’re not saying much about this thing. It’s been rumored for a long time and while it’s called a “Facebook killer” but it’s likely to be something very different because why go after Facebook head on?