Flickr My Background is a neat little tool which checks your Flickr account every hour for uploads to your Flickr account and uses the latest photo as your Twitter background.
I’ve tried it out and it definitely works well however you may need to set your custom background image by going to your Twitter design settings page, click on “Change background image”, then click on the image box that appears. Also, due to a bug in twitter, you’ll need check off ’tile background’ before clicking save. You can always un-tile it later.
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