You can specify which pictures to choose from:
Individual pictures on your computer.
Folders containing pictures on your computer such as ‘My Pictures’.
Flickr photo sharing – selecting pictures by person, tags, sets or just plain random. You never know what you’re going to get next!
Facebook – your friends photos on your desktop!
Vladstudio wallpapers – choose from the coolest wallpapers on the net!
Any Media RSS feed – choose pictures from sites like DeviantArt, Photobucket, LOLCats and Zooomr amongst many others!
Phanfare web albums – keep up to date with your friends and family.
smugmug photo galleries – yours, your friends, anybody’s!
Picasa Web Albums – choose from specific albums or any search text.
Webshots – if you’re a Webshots user, you can choose from your online or downloaded photos and collections.
Google Image Search – get pictures from anywhere across the internet.
Bing Image Search – not a Google fanboy? Then Bing is for you!
Yahoo! image search – the internet is your oyster!