PicPost ($1.99) by Altaf Sayani is an app that allows you to quickly share your photos to multiple sites at the same time.
When PicPost is launched, you'll need to immediately set up your social network accounts on it. Currently, the app only supports three sites: Posterous, Twitter, and Tumblr. Though personally, I find that emailing to Posterous is the easiest method, but some people out there don't dig it.
Enter your credentials for each, then hit the Save button at the top. Then make sure to toggle the services on by tapping the ones you plan on using. Now you're ready to share!
Select a photo from your device or take a new one and add a quick line to go with it. Then send it. That's all there is to it. When it's sent to Posterous, the description you sent will be the title of the post. On Twitter, it will be the tweet and the image will be sent to Twitpic. I did not send to Tumblr because I'm more of a Posterous person, but I'd imagine that the result would be the same as Posterous. The uploads are done in a reasonable amount of time, depending on your connection speed.
The big drawback of this though, is that you can only upload one photo at a time. I tried sending two photos together but only one shows up. So if you have a lot of photos to share, you're going to have to do it all separately. And you have to manually remove each image you just posted to get a new one up.
If you're looking to upload to a certain site for Twitter such as img.ly, yfrog, twitgoo, tweetphoto, or anything else, you're out of luck. The Twitter photo upload is non-configurable so you'll have to deal with Twitpic.
For Posterous, it was kind of disappointing that you can only add the title to a post, I found no way to add some text to the body of the post to go along with the picture. Sometimes you have the need to make a small blog post out of a photo, but that's not what this app is for.
The big thing that this app has going for the developers is that the interface is nice and easy to understand, and actually ready for the iPhone 4 Retina Display.
But for the price of $1.99, I'd expect more sites (although with Posterous you don't really need anything else since it auto posts to everything), choice of Twitter photo site, and the ability to add multiple photos, and perhaps a body text option at least for Posterous and Tumblr. I'm actually surprised there wasn't Facebook integration, since that's the most popular thing nowadays.
For the current price, I'd wait til there are more features. Or if this is all that there is going to be, the price should be dropped to free, or at most $0.99.