Finally I got to create a public repository on GitHub for all my public domain utility tools (I had to fiddle quite a while with
git filter-branch to extract all the 'safe for public' stuff from my home repo).
At the moment the following four scripts are available:
Creates an XML wallpaper file with a slide show.
Advanced picture uploader for Google Picasa, capable of watermarking images.
A simple script that sets a random image as current wallpaper.
Updates EXIF date in JPEG images according to the file name.
Please welcome: github.com/yktoo/yktools