Somewhere I read this that google devalue footer links thinking of them as signature links. So I dont think it matters to put those links in footer. But, I saw many companies put a signature link in footer of their client's website like this- WEB DESIGN COMPANY-- this is I think a poor strategy, google is wise enough to devalue or ignore such backlinks.. A web design company can work on 100 websites per quarter and that way they are getting atleast 400 such backlinks per year, who can match with them then? So google never value such urls.

Hope it helps....

I changed all footer links recently like this--- Expert Village Media
No url, no link back.. no keyword.. and I saw in analytics that people are searching this keyword in google and coming to our website. Google is happy, client is happy, and I am also getting my traffic.

Amit