Any value to duplicate signatures?

[Doug Barton]

I am pretty sure the answer to this question is "no," but I thought I'd 
ask just in case. I've attended a conference for the last 2 years where 
there was a PGP key signing. Several of the people who signed my key 
last year were present again this year, and sent me signatures again. 
The signatures are from the same keys, same certification level, 
everything. The only thing different is the date of the signature 
(obviously).

So the question is, what value, if any, would there be to importing 
those signatures, and sending them out to the key servers? I know that 
the various -clean options will strip that down to the most recent, I'm 
just curious. :)

Doug