Don't forget to check out The Sketchbook Challenge blog this month. The theme is Urban Sketching, which basically means sketching on location; no matter where you are or what's going on around, sketch whatever scene is in front of you....landscapes, buildings, people, a potted plant, a child swinging on the playground. It's a great way to enhance your drawing skills.
There's also a Sketchbook Challenge book, due out any day now. Click this link to find out more.