To my mind you will only provide a WAY to discriminate a fake ichimunki from the real one
( if you're the real one ;-)
But will people WANT to check if it's the real ichimunki by looking for your sign in the post ?
Will they ever KNOW that you always sign your post ?

If I go on betterperlmonks.org (sorry for the blasphem vroom)
create an ichimunki account and start posting crap,
any betterperlmonks.org user that will see your signed posts here on perlmonks will think :
'why is he signing his post ?'
and maybe 'hey his posts seem to improve'
but they will more likely think 'oh no ! ichimunki is posting crap here too...'

Now for a purely technical aspect :
I don't think that the average 'joe' knows how to use PGP,
(I'm not even talking about GPG...)
And I don't think that those who knows will make the effort to try to get your public key (where ?)
to verify your sign post (why ?)...

"Only Bad Coders Badly Code In Perl" (OBC2IP)