All picture requests do indeed go to the Picture Request thread. However, the background of Depths Of Oddworld contains a lot of rockart. The music will return when a) Sligslinger fixes his equipment, or b) I can have access to a host that will host the music files I have without collapsing on me.
Oddworld sites? Do you mean fansites? If so, then I definitely recommend the following:
Hayley's
Depths Of Oddworld
Abe Babe's
Oddworld-Web
Alcar's
Oddworld Universe
Xavier's and Max's
OddBlog
There are others, which can be linked to from those pages, but these I would say are the big ones. OWU is a little minimalist at the moment, and OddBlog is merely a news-reporting site. For more official sites, there's only really Oddworld.com. I'm not even sure if Microsoft have their Munch's Oddysee page anymore. Even if they did, it's doubtful any of the features still exist on there. Cue somebody to come along and prove me wrong.