Responding to myself after some more Googling:
Ulrik Petersen wrote:
If Larry Lessig, Professor of Law at Stanford, thinks you can dedicate
something to the Public Domain, then you probably can.
An article is available at Linuxworld where Prof. Lessig says in
(almost) so many words that you can dedicate software to the public domain:
http://linux.sys-con.com/read/38116.htm?CFID=176814
From the article (talking about software):
"It is therefore perfectly permissible for the owner of a copyright to
do nothing with it. And it would be perfectly permissible for the owner
of a copyright to give it away -- to dedicate it to the public domain.
(And if you'd like to do that, Creative Commons
<http://creativecommons.org/license/publicdomain-2> will help)."
Ulrik Petersen
I am not a lawyer.
