upsidedown is a simple Python program that takes input from stdin and pipes it to stdout reversing latin characters and punctuation marks by using latin character based symbols from Unicode so that an impression of upside-down written text is created.
Simply save this program, make sure Python is installed and add the script to the Kopete pipes plugin (see attached screenshot).
You can enhance the script by adding special substitution rules (see variable TRANSLITERATIONS which has an example for German sharp-S).Support for diacritics is included but fails on common rendering systems for most cases as no rendering rules exist for these artificial instances.
This needs KDE 4.2 or above.
Feel free to comment.