Posterous, the popular free blogging platform that's been called many times in the past the "real alternative to Tumblr", just got an official iPhone client. The app, simply called Posterous and free in the App Store, allows you to send posts with any kind of text and media in it to your Posterous powered blog. The app is meant to be running on devices with iOS 4 multitasking: you can select material to upload to your blog, close the app and open another one, the upload will continue in the background.
Posterous for iPhone also lets you assign tags to post, together with geotagging metadata and "private" attribute. You can manage multiple sites (including private ones) and create group sites. The app looks really nice and polished, with navigation tabs placed right above the keyboard to easily allow you to enter content in your posts.
Posterous for iPhone is free in the App Store.