Use SimplyBox
http://www.simplybox.com
Use Glogster
http://www.glogster.com/edu
example:
http://thekinderkids.wikispaces.com/
Use a wiki (like wikispaces)
http://wikispaces.com
examples:
http://room9nelsoncentral.wikispaces.com/
http://glovely.wetpaint.com/page/Patterns#link
Use Yola or another Easy Website tool:
http://www.yola.com