SERoundtable has covered a couple sessions on linking from SES San Jose and the overall theme I’ve been getting from each of these sessions is to keep your links looking natural.
Both Matt Cutts (Google) and Tim Mayer (Yahoo) have said that varied incoming anchor text is the most natural, so if all your links are incoming with the same anchor text most likely the link weight will be devalued. When working on building links aim for the most natural approach possible – this means human interaction and less automation. Vary your anchor text, ips, domains, location of link (footer vs content), and the location that link is pointing to. As search engines get smarter and filter out unnatural linking methods, your hard work will pay off.
This goes for reciprocal links too – link for your visitor and not the engines. If a resource is worth linking to, then link to them. Don’t worry about hoarding PR or protecting outgoing links, link freely as long as it benefits your visitor.