Drupal-based efforts:
If a library is in Idaho, they can get a 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

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)

These projects utilize the Plone CMS –
In Oregon, Colorado, Illinois, or Texas, public libraries can get a free 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.

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 – that also utilizes Plone.