Paint Park (already out on the PS3) is coming to the Vita this week, as the first of a series of free apps from Sony. You can take photos and touch them up with the paint program, or create mini works of art on the touchscreen and interact with friends on them. After that will come Treasure Park a make-your-own-puzzle app that you can use to share the results with your friends and let them try out your challenges.
Lastly comes an app called Wake-up Club that sounds rather strange. Part-alarm-clock, part-social-app by allowing you to set alarms on your friend's Vitas. Can't see much use for that one, unless you give your kids a Vita each - but I'm sure the Japanese can set Monster Hunter (or Ragnarok) MP dates. Pics and more detail on the Sony blog.