Linux based multi-user computing lab setup by me for students at a rural school in India.
Centrally managed, multi-user system.
2Ghz CPU + 2GB RAM shared by 4 students
Each terminal/user has a 15" LCD panel and fullsize keyboard and mouse.
Built completely from COTS components and cost under INR 9000 (USD 200) per seat.
Best Cost to Performance ratio - Beats OLPC and nComputing based solutions hands down in performance.