Add an "include current date/time" button to confluence rich text editor (or a standard markup as in mediawiki)

Many of our users share their thoughts by editing their wiki pages and signing their additions.

It would be very useful to have specific markup helpers as in wikipedia:

You should sign your comment by
appending four tildes (~~~~)
to the comment so as to add your
user name plus date/time:
: ~~~~
Adding three tildes (~~~) will add
just your user name:
: ~~~
and adding five tildes (~~~~~) gives
the date/time alone:
: ~~~~~