To all,
I have been involved with reciprocal linking for over 8 years. We have worked with hundreds of domains, in a lot of very different circumstances.
Here's a fact - most of what is written about linking and SEO is total bunk. The "experts" in the SEO industry who are the most vocal and get the big time speaking gigs, write the books, etc. are some of the most confused, especially about reciprocation and it's affect on the engines. Some of them have obvious conflicts of interest, and promote their own solutions, regardelss of the excess cost to their clients.
Here's what we have learned, in a nutshell:
Link to and from as many home and real estate-related sites as you can, be it via reciprocation, or other legitimate means. That is proper BRANDING, not just reciprocation for SE purposes. The WWW is a network of links.
The SE results DERIVE FROM good branding-focused linking practices, combined with good content and optimization.
Do not even consider PageRank in this. That is a Google-centric number and not even reliable. You can get different PR for a site, depending upon the server delivering the info.
There are other engines. MSN is easy to rank in with some basic work. YAHOO! hard to figure out.

Anyone who has some tips, pass them along. Google prefers established sites, so, the time to start getting established is NOW.
DO NOT enter into link networks where everyone else posts the exact same links. Bad news. Not an automatic penalty, but risky.
Here's a multi-page document that was specifically written for real estate professionals, using real estate examples:
Search Engine Optimization Basics For Real Estate-Related Websites I hope it helps.