Here’s our weekly digest of interesting and useful links from around the web. Enjoy, and have a great weekend!

• Retail spending is slow, but people are still spending.
• 50 years of LED tech. (via @Carolyn LaWell)
• Lichens!
• Related: Reflecting pool at the Lincoln Memorial drained due to algae invasion.
• Science makes it true: To be more productive, watch cat videos on the internet.
• London wants its own High Line, but underground.
• Above: Water rates are going up. They won’t stop. (via CLCA)