This is a great site! This picture in particular has two great things: crates (that are on wheels!) and dry erase dots on the table. Great way to let kids show and do their work. Maybe even put them on students' desks? What a great idea!
crate seats: great storage! All you need is... crates (wal-mart), thick foam (it comes as a roll, hobby lobby), plywood to fit in the top of the crate (home depot, they cut it for you for FREE), scissors, and a staple gun... then go to it!
CLASSROOM ORGANIZATION: This would be a great seating option for a small group table in the back. The pull out drawers in the crates offer storage space. Perhaps you could keep small white boards and white board markers in them.
Classroom benches- three different levels so everyone can see- the top level is a milk crate + a half one zip tied together- middle is a crate on the side and the bottom is a crate flat on the ground- 3 crates for each bench- I love them! (Picture only)