This is a bit old, but I haven't had time to dig in and play with the public version of Aviary until recently. After a long beta period they've officially taken the wraps off of Phoenix, their bitmap editing tool and consolidated everything under the aviary.com domain. The launch not withstanding, the Aviary crew has been very, very busy and Aviary continues to be one of the most innovative set of RIAs that I've seen.
The beauty of Aviary isn't the set of tools or the fantastic design and branding - though those all help - but how they're building up their community. On their blog they've got a ton of samples to get you started. And baked into the tooling are all the steps that you take to create the end result. That means that if you want to, you can share all of the steps and settings that you used for your masterpiece. New users can look at that and figure out exactly how to get the most out of the tool. They've become famous on digg for their various creations. They've also started to roll out a way to make money by pricing the service at a couple different tiers. Hardcore users can choose between Green, for the people who mostly use Phoenix, and Blue, which gives you access to the whole suite of tools.
But one of the subtle beauties of Aviary is that it's all cross platform. One of the reasons I've been using it lately is because I'm trying to switch more of my work to Linux. There just aren't a lot of great design tools for Linux, but Aviary's entire suite is built on the Flash Player and so it's cross platform. They've even got a Firefox extension that lets you do things like take screenshots from the desktop and helps blend the browser sandbox with the desktop. It's a pretty good bridge between online photo editor and the functionality people expect on the desktop.
So keep an eye on Aviary. They should be releasing more of their tools soon, but I think they've really nailed a lot of big parts of rich Internet applications. They've got a very functional tool, a rich user interface, and a passionate design community.
Thanks to Flash Speaks Actionscript for the reminder.