We have seen number of Twitter resources that allows you to download cool looking Twitter background images. However, most of them offer non-editable JPEG or PNG background images that leave very little scope for customization. TweetStyle fills in for that and offer Photoshop PSD file download for Twitter backgrounds in their listing.
More Resources: Twitter Pattern – Twitbacks – Flickr as background
It has impressive collection of professional looking Twitter backgrounds. At the download section, you can find link to download respective Photoshop PSD files for many listed backgrounds. If you know little way through photoshop you can easily create highly customized Twitter background using downloaded PSD file. Why wait? Grab PDF file of that customized Twitter background at TweetStyle. Here is video explaining installation process: