Here are some public data centers and ISPs offering various shades of green computing

Cleanbits - A worldwide listing of "Green hosting providers".

Ecologee - A worldwide listing of "Eco-ISPs"

Aiso (Afforadable Internet Solutions Online) - a "A 100% Solar-Powered Data Center" in California includes innovative air and water cooling. IBM says AISO "Achieves a 60 percent reduction in power and cooling costs through virtualization-based data center consolidation… Increases average server utilization level by an estimated 50 percent"

ecoSky - Oregon facility using a combination of on-site solar and purchased renewable energy. An ecoSky client promotes its "green website".

elfon.com - Utah facility advertising "Green Web Hosting - 100% wind powered" and displaying a number of "green" logos.

Sustainable Marketing - California company advertising wind-powered hosting.

Anthenaeum's Ecological Hosting - UK