Rock Martinez worked outside Posner's Art Store (1025 N. Park) for maybe five hours yesterday afternoon... with some help from his brother. Other artists, fans, and friends stopped by. Here's a design (pasted over a photo of the storefront) that shows roughly where he's aiming:
The scene not long after I got there at 2 PM:
And at 5:45:
Rock said he wasn't planning to work today, but he'll be back on Monday. Stop by then if you can!
Update (July 12, 2011): The mural is done.