BuyMeBlocks: a living digital graffiti wall

How it works
A wall you can buy by the pixel
- 1 credit a pixel. $1 buys 100 credits.
- 24 h of protection with every placement. Each extra day costs what placing it did, up to 30 days, and anyone can chip in.
- Replace art by covering all of it. Unused protection is refunded.
- Layers: old art shows through transparent new art.
- Shields block one attempt; the challenger pays a fee.
- Move credits: one with every placement bought with purchased credits, and some for visiting; each moves any of yours.
- Visit daily for free credits.