guestbook script[/link] which always forces you to a first preview before
it would accept any entries. I've only implemented a static hidden field
which is only sent together with the preview page so no automated script
(aka "bot" ) can "know" it needs to be posted, too, before the sent data

I do like this idea. To parse it out a little, here is how I understand it:

1. Comment form is filled out and submitted to the processing script.

2. If processing script does NOT find a "preview" flag

a) A random preview flag is created
b) flag is assigned to a session variable
c) the preveiw page is shown with submitted information and a hidden field that contains the preview flag.

3. If the processing script DOES find a preview flag.

a) If posted flag matches session variable, form is submitted and thank you page shown
b) If posted flag does NOT match the session variable, form is not submitted and the spammer routine is triggered

Phil