http://www.chibrow.com/

ChiBrow is a Web browser designed
for children, to allow them to safely
explore the Web. It does this by
giving parents the ability to define
where the child can venture. Unlike
filters that prevent the displaying of
Web pages containing harmful
keywords, ChiBrow disallows any
sites/domains that haven't been
specifically approved. It comes with
preselected safe sites, and in the
registered version, updates to this list
are sent to you. 

Note: The default supervisor
password for the shareware
version is chibrow. Be sure to
change the password before
allowing a child to use this
program. 

Minimum requirements:
Windows 95