3DLES offers project management, educational support, building and scripting for educational projects in OpenSim.
Creative Twists Designs offers design, building and other services for companies considering Second Life and OpenSim deployments.
Daden offers consulting, design and building services in virtual worlds, with particular expertise in the areas of web and real world integration, and creating interactive virtual personalities.
Designing Digitally is a development firm that specializes in virtual worlds, e-learning, and 3D training simulations.
US $150 per month for a four-region simulator on the Starlight grid. Building, consulting, and Second Life migration services also available.