Plixi, formerly TweetPhoto, just released their iOS application for the iPhone and Touch. The app lets you take photos and tag them with your current location. You can then see your friends around you and even snoop on others who are uploading to Plixi in your general vicinity, provided they’ve made their locations public. If you smell a problem – namely “network effect” – raise your hand.

The new features include:

Publish pictures to Twitter and Facebook
Add pictures to places or events near-by
View pictures and people nearby
Create user-defined events and places
Upload pictures without having to check in
Tag friends in pictures
See what friends are doing
Get notifications around friends and pictures
View public and celebrity photo streams
Comment, Vote and Favorite pictures