Lately I've been concentrating on putting high quality content and links in very beautiful, well designed footers. Once the designers and development team is done with the creation of the footers, then I make sure that all the SEO elements are present in the footers. There is no doubt that a unique footer with a beautiful design and will not only attract the attention of the human visitors, but also through proper SEO practices the search engines will give the entire site more authority due to the number of keywords, relevant content and links in the footer.
Examples of some of our footer designs:
Google and other search engines are quickly moving away from just reading the code of a website, and trying to determine what really makes a site aesthetic, easy to use and relevant. By picking apart your footer, the search engines will notice that your site is not just one of a million other sites that are doing the same thing. The search engine will see your background graphics, keywords, anchor text and other elements and rate your site accordingly within the Search Engine Result Pages.
One great tip when considering how to optimize your footer would be to use footer links for some of your more important, or hard to find information. Within the anchor text and the title attributes of your links, you might have more success using alternate text or longtail keywords instead of your top anchor text and alt texts. A good way to determine what types of anchor text and longtail keywords to use would be to research and think about what types of "phrases" people use when searching for your product or service. These phrases should always be relevant to the link (if you are using search engine friendly urls (SEF's)) and the content on the page. So in other words, don't make your title attribute and/or anchor text something arbitrary because you want to rank well for it, make the text a phrase that describes what the page is about, but in a fashion that will use a phrase that people might search for.
I have used footer links extensively through most of my sites, especially the larger ones. One thing I do however is not use the same anchor text links in my footer as I do in my main menu. I also do not link to each page of the site in my footer. What I have found to be effective is to create "anchor phrases" to the top six or seven pages and use them in the footer.
Another thing to avoid is overloading your footer with to many links. It is believed that the most important content and links on your site should be in the very beginning and the very end, so use this space sparingly. I would suggest limiting the footer menu to under a dozen links. I would also stay away from repeating links, as it will look spammy if you put 5 links to the same page in your footer.
New scripts are able to see if a visitor came from a search engine, and what keyword they searched for. These scripts are quickly becoming the future of SEO, and are very valuable in determining the anchor text that displays in the footer. An example of this could be if someone searches for "big round blue widgets" and you have a widget store so your site comes up in the listings, all the anchor text in the footer will be related to "big round blue widgets". There are scripts that do this such as the Drupal module keyhavior, but I have not seen any that work perfectly without some custom coding.
The best way to think about footers when considering SEO is to provide the best resource for them in your footer, and provide them with info that will help your visitors the most. This way even if these links aren't given as much weight as all the others on your site, at least your site is gaining value from those links by providing good quality information that will keep your visitors on your website.