NOPE! just make sure that you are NOT linking to sites that are either been banned, or is regarded as spam sites.
it isnt harmfull as my exprieces but it hasnt got any advantage for PR or any traffic for your site...
It doesn't harm your website, and it maybe help the pages you linked to. Just as the directories, they give links to others with no links back required. But if you provide useful links to visitors, I think it will give you some traffic. I remember there is 1 website which provides the links for most of the useful and common websites, so when people want something, they will go to his website first.
Search engine's point of view the best link would be the most of the "unrequested inbond links" that come out voluntarily because people find great content on particular site.