Sorry for spying on your thread (I saw it on the Wiki Activity). Just yesterday I created a series of "How-tos". One of them was for signatures. Maybe it can help you. I'd love it if you'd give feedback.
You're welcome! If you want me to change anything (IE: Make the sprite link to your blog instead, change font, add in something linking to your message wall, etc.) Tell me. Otherwise, I'll just show you how to make it your sig.