My screen name is CellarDweller.  I picked it because my computer, phone, TV, DVD/VCR, all my CDs and DVDs, CD player are all in the cellar of the house, so that's where I spend my nights when I'm home.
My avatar has almost always been my picture.  There were other ones, but I can't remember what they were, it was so long ago.  The pics that end up as my avatar are always taken of me at Brokie gatherings.  It's currently a zombie for Halloween, but that will change as of tomorrow.
The text under my avatar changes occasionally, depending on my mood.  I believe the text I had the longest was:  "City boy's mentality with a cowboy's soul".  I have it because I believe it matches my personality.  My mentality is definitely "city".  However, I love putting on my cowboy hat and boots at a Brokie gathering and going horseback riding, hiking, and being out in nature, which is where the "cowboy's soul" comes in.  It's currently the Halloween themed "Zombies - Eat Flesh", which is a spoof of the Subway franchaise line "Subway - Eat Fresh".  Prior to that, there was a dedication to Rich that said "Heaven Has a New Angel - RIP Rich".
My signature line has changed a few different times during my time here.  My prior one is the one I've had the longest.  I do want the right to marry, and that's what the line signifies.  Currently it's a group of shadowy zombies approaching for Halloween.  As of tomorrow the marriage equality one will be back.