They're a little old-school (OS-Tan girls are *SO* 2004) but I want to resurrect the concept. The OS-Tan girls were a manga phenomenon a few years back featuring Mac and Windows characters in sometimes raunchy narratives (imagine what an anthropomorphized virus could do to a Windows-Tan...) This is the first instance I've seen of Linux-Tan girls.
The Slackware-Tan girl is second in a series of 11 Linux-Tan GDM themes.
Others planned: openSUSE, ArchLinux, Gentoo, Fedora Core, Red Hat, Mandriva, Debian, Knoppix, and generic Linux.
The original artwork belongs to Juzo-kun (http://www.jkhp.it/) and is released under a Creative Commons license. If you take this package apart for other projects, please credit the original author so she and fine artists like her will continue to share their talents with the rest of us.
The GDM format was borrowed from Ubuntu's Human Circle of Friends by Mark Shuttleworth and company and the badge is by Peter Mathijssen (http://www.gnome-look.org/content/show.php/Stickers+7?content=56776).
Feedback would be appreciated since this GDM theme is running in a bit of a quirky environment: Darwin GNOME on a Macintosh. One of these days I'll figure out how to get a real honest-to-goodness Linux partition dual-booting alongside PowerPC OS X. No luck so far... :(