Reciprocal Link Spam

Practically every day I get emails from people asking for reciprocal links. They invariably start off with:

I recently found your site http://www.marketingtom.com and am very interested in exchanging links. I've gone ahead and posted a link to your site, on this page:

At which point I check and find that I am listed at the bottom of a long list of other websites. These emails always finish off with the folloiwng paragraph:

As you know, reciprocal linking benefits both of us by raising our search rankings and generating more traffic to both of our sites. Please post a link to my site as follows:

One thing that rankles me is that every time I use my Google Toolbar cached tool I find that these sites have not even been listed on Google. So, we have a situation where:

1. They want me to put a link to them from one of my web pages which has a Google PR rank of 6 or even 7.
2. The value I get from a link, even if it has a good PR ranking is minimal as there are so many other links on that page.
3. What the hell doesHome Insurance, a Czech hotel or Work at Home Ideas have to do with Internet Marketing and Blogging.

In this instance reciprocal linking only benefits the site that asks me to create a link to them.

What to do?
I just tend to add them to my Yahoo! email spam list (they are almost always bulk spammers).