If you follow some of those, how do you say, "influencers," on Twitter, you may have noticed a "w/" popping up in their tweets lately. It's generated by a new app called With, a side project hammered out by the developers over at Path. For those unfamiliar with Path, it's a photo and video-sharing tool for your own private network of close family and friends that's HQ-ed in SoMa and headed up by early Facebook team member (and co-inventor of Facebook Connect) Dave Morin. Its goal is to allow you to control the sharing of your most personal moments, and the app's now at over a half a million users. 

Morin calls products like  With "Path Shorts," a nod to what Pixar does with its Pixar Shorts before the main feature (which is Path). He believes that successful work environments allow time for free exploration and toward that end, has instated weekly "Hackathons," set-aside hours for employees to go wild on side projects. "I like to think creative freedom inspires more creativity," says Morin. It's during one of these "Hackathons" that With was born. The app launched earlier this month and is now enjoying a cadre of high-profile users like Ashton Kutcher and Kevin Rose.  

The With app, well, tells people who you're with. It's all based in Twitter, and has a similar use case to tagging people within Facebook places or mentioning friends in Foursquare check-ins, except it doesn't necessarily need to be tied to a specific place or business. (A recent example from Mr. Kutcher: "hanging with the winklevoss' w/ @winklevoss @tylerwinklevoss http://with.me?CGX"). You can also snap a picture of who you're with and what you're doing (using premium lenses to make your photos more flattering). In a funny back-to-the-playground feature, the app lets you keep track of who you hang out with the most, and those with the highest marks are dubbed your "best friends." You can also "like" posts if you're in support of a hangout. The newsfeed looks similar to Path, with a rolling list of photos and updates. 

Check out With for yourself at with.me, a url they had to acquire from the government of Montenegro (.me is the Internet top-level domain for the country) by convincing them they were going to do something "really cool" with it.