John’s Background Switcher is a freeware tool which periodically changes the background image on your computer. You can specify which pictures to choose from, or how you want them displayed.
* 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.
* Facebook – your friends photos on your desktop!
* Any Media RSS feed – choose pictures from sites like DeviantArt, Photobucket, LOLCats, Zooomr, etc.
* 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 photos.
* 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!
You can add as many pictures sets from as many different places you like to the list and decide how you want them shown. Additional fine-tuning options are available from the ‘More Settings’ dialog where you can tweak till you heart’s content. Maybe you want a 3-month calendar on your desktop, your backgrounds always to be sepia or a cork noticeboard look – whatever you want is probably there.
While I have not tried it, you might want to check it out.