An SSI exec produces no less (in fact, a bit more) CPU load than a CGI script.

You can actually do this purely in SSI, but it is going to be a very, very ugly hack:

<!--#include virtual="/poll.shtml" --> /poll.shtml:

<!--#if expr="\"$REMOTE_ADDR\" = /1\.2\.3\.4|5\.6\.7\.8|9\.10\.11\.12/
+ -->

<h1>Poll RESULTS go here</h1>

<!--#else -->

<h1>Poll FORM goes here</h1>

<!--#endif -->
[download]

Then the vote CGI would have to rewrite the file, updating that regular expression along with the poll results every time someone casts a vote..

Well, it works - but as I said, that's rather very ugly a way to go about this.

Makeshifts last the longest.