There is an interesting thread over at WebmasterWorld on the topic of link building. One of the members there said he has totally stopped obtaining inbound links due to believing they will not benefit his site.
In response to that some senior members over at WMW responded:
The general rule is to link for the benefit of users, not for the benefit of PR.
I don't believe that the restrictions are as tight as some imply.
Basically, an inbound link in and of itself cannot hurt you. Once the inbound is reciprocated, issues can arise, depending upon the nature of the other site/page, and the nature of your site/page.