EDIT: this application is no longer maintained, rather use this initiative.
I created my first facebook app.
1. It loads the RSS from my username
2. Uses deviationnumber to load real (bloated) deviantart page
3. Using AJAX to get the thumbnail out
4. Pushing that into an overviewpage.
*slow!
*no facebook setup yet, so no personal application possible
If someone has an idea to accellerate this method (I did not find a deviantart API, hence this slow solution) please let me know.