Go to this site to see a variety of play structures. Click on each structure to see the dimensions. You'll even find bicycle racks. (Scroll down on the left to find more). Example: Click on Commercial Structural Components, then on Mountain Climber and you will see this picture:

This site is organized around creative play, active play, and quiet play.

Example: Dimensions: 11'6"L x 9'6"W

Outback Play Centers, Sun Prairie. Hand Walker: Stretches the abdomen and builds strong arm and back muscles.            DIMENSIONS: 3'6" X 8'6" X 4'6" high

http://www.ag.uiuc.edu/~vista/html_pubs/PARK/park12.html Go here to find a chart with space requirements for organized games such as soccer, tetherball, etc. It gives the length, height, and approximate space required for many different playground equipment.

http://www.arborday.org/trees/ Use the find/buy tree on the left to choose the perfect tree. Click on the picture of the tree to find the dimensions.

http://forestry.about.com/library/tree/bltredex.htm?PM=ss11_forestry North America's Top 100 Trees

Click on a tree to see how it would fit into your playground. For example: A small, upright round headed tree. Graceful and dense in appearance. Tolerates many soils. Good lawn tree.Example:                                   Height: 20-25 feet                                   Spread: 20-25 feet                                   Growth Rate: Moderate                                   Fall Color: Red/Orange/Yellow                                   Flowers: Inconspicuous                                   Fruit: Winged seed 1" long