Rural Bus Stop Shelter

I have been wanting to build a bus stop shelter for my kids, and have been searching for plans for just a basic relatively inexpensive shelter. Maybe someone could put together plans for a simple shelter that will fit 4 people, with maybe a ledge for sitting on. Roof doesn't have to be anything fancy - just corrugated metal roofing would do. Reclaimed pallet wood maybe?

Something like this:
http://www.flickr.com/photos/nationalrural/1092548791/

http://www.flickr.com/photos/82194366@N00/2274825306/

http://www.flickr.com/photos/danwoodphotography/3501453683/

Thanks!