Collaborative web design and hosting initiatives for public libraries
Free, statewide efforts for public library web sites:
Idaho's e-Branch in a Box
If a library is in Idaho, they can get a Drupal based website for free through “e-branch in a box” (info here - http://help.lili.org/). Check out their current sites here - http://help.lili.org/node/137
Missouri's Real EZ
In Missouri, libraries can apply to participate in a pilot program, Real EZ, to get a website through the state library (nof here - http://www.sos.mo.gov/library/development/realez/requirements.asp)
In Oregon, Colorado, Illinois, or Texas, public libraries can get a free Plone based website through the Plinkit collaborative in their state. See here for more info - http://www.plinkit.org/ - scroll down to Partner Sites on the left-hand side to find each state’s Plinkit site and contact info.
What is Plinkit? Plinkit is the web authoring environment that public libraries in partner states use to create smart, new web sites for their patrons. Plinkit stands for "Public Library Interface Kit." It's also a fun word to say. Plinkit is built using Plone, an open-source content management system.
Public library web sites are created and edited right through the web, using built-in text editors and other powerful features that make a tough job simple and give patrons a clean, usable, web site where the information delivery is the true and proper focus. Feel free to check out the demo version.
What is the Plinkit Collaborative? The Collaborative is a membership organization (at the state level) that formed in July 2006. The goal of the Collaborative is to provide Plinkit to public libraries beyond Oregon (where Plinkit started) and to pool funds in support of software development, training, documentation, and marketing activities.
Who is Currently involved? Four states currently participate in the Collaborative: Colorado, Illinois, Oregon, and Texas.
LITA Presentation - From Plone to Plinkit to Public Libraries: A Tale of Four States 
In Iowa, they have PLOW (Putting Libraries on the Web) that provides websites and e-mail services to public libraries - info here - http://www.statelibraryofiowa.org/ld/plow - like Plinkit, it also utilizes Plone.
The Northeast Kansas Library System has been working with smaller libraries in Kansas to create nice, functional websites using WordPress. They call the project Kansas Libraries on the Web (KLOW) and you can read more about it here.