a somehwat similar project to the recently blogged rixome from spain is foundcity.net.
With Foundcity you send photos and text messages from the street to your personal map and tag it, share it, blog it and more Foundcity is a social mapping tool for creating a personalized map of your life on-the-fly. Using your mobile phone, you “tag” or capture photos throughout the day, label them with any words you want, and send them to your map. At home, you access and customize your map, which you can share with friends, keep private, or publish openly.
if i understand correctly this will not allow people to pick up the tags from onsight. but it leaves you the opportunity to blog this info and create your own map of your city. so far they do manhattan, brooklyn and san francisco.