MyMediaPlayer is an Adobe AIR app that can play Hulu.com content. Since it was written in Adobe AIR, it can also be run on Windows and probably Linux. This app uses the RSS feeds that Hulu.com distributes to show you the content available on Hulu.com but on your desktop.
When you first launch the application, you will be asked to type in your e-mail address so that you can be sent a password that you will need to use the application. The process is quick enough that this doesn't become a nuisance. After that, MyMediaPlayer will show a list of TV shows from Hulu.com. If you click on any of the shows, you will be taken to an episode list from where you can play them. There is also a tab that takes you to the available movies. With version 2.0 of MyMediaPlayer, you can watch Hulu.com on full screen.
In my testing, I was able to get all the way to the episodes list. But I couldn't get the application to play anything. I gave it plenty of time and I even tried with several different shows and episodes. I can browse just fine on Hulu.com.