Site Map Link - Does visibility & placement matter?

I've been reading up on site maps and their benefits. If you go to www santarosasmog dot com, you will see a small checkered flag image which appears very near the top of the source code. As I really only want to put in a site map for the sake of seo, does it matter if I make that image a link and link it to a site map page. It is not important to me that site visitors see the site map, only that engines find it. Can achieve this as I suggested?

Well, I personally don't suggest that at all.

That site has main categories that must be clicked to navigate the site. Personally, I would rather find a site map page and browse that with this site layout the way it currently is.

Therefore, I would make a sitemap part of a feature on the page for someone to use.

Site maps aren't just for the engines. They have great benefits to the end-user as well.

I can certainly respect that. Looking at the layout then, where might you place the link? Does it matter where in the source code the link appears to the site map? I thought of something like - Site Map / TMH Design in the upper right corner with it being two links, one to my portfolio, one to the site map?

I'd place the site map "high" where the spiders will get to it. It's an important page for spiders and users alike, so give it its due.