Try
www.schoolfriends.com for an example
Note, schoolfriends.com only covers the South East Asia, Australia, New Zealand,
South Africa, UK/Ireland regions, but excludes North America (U.S./Canada).
However there are probably other similar sites around.
However that site may be a little too much involved for what you want - it is a
"where are they now" type site to track down old school-friends.
For your reunion site, you can probably do the database with the results wizard
in Frontpage. If your server allows the upload component, that solves the issue
of the user uploading a photo. You can get the db to display photos - but this
is not really a straight forward process unless you know a bit about the database
functions - there is a procedure on how to do it in the FP Help, and also in the
knowledgebase at microsoft.com
Regarding secure server/database you might need to discuss this with your host,
depending on what they offer in this respect.