I talked to a fellow webmaster recently and he told me that he quite often links to high authority sites from his articles and that actually improves his SERPs! I was really surprised by this, because I've "grown up" thinking that the less outbound links, the better.
I know as a fact that outbound links to very high quality authority sites (government, health, .edu, trade organizations, etc...) has a beneficial effect for ranking as long as they are highly relevant to what your site/page is about.
...In fact here's an example of how I might use it for my client's benefit...
Let's say for example my client is an Arborist. Someone searching for that type of service will more often than not be aware that there are municipal bylaws in place for protection of trees. So, realizing that those potential customers of my client will be browsing municipal bylaw pages I go to that municipal page and analyze the copy written content. Then on my client's page I will write the content in such a manner that the "common ground keywords" that are prevalent on the municipal site are also included in the text I write on my client's site and also link out to the exact municipal page that answers the question the searcher needs answered.
This creates a wonderful effect of nudging my client's page up to the top with the "authority" municipal government page and frequently, as long as the searcher is attentive, they realize their "luck" that not only have they found their answer but also; "oh look lucky me there's even a result to a company that offers the exact service I'm looking for and now won't have to go looking for that too".
Sweet example of Website Optimization. There are MANY MANY ways of improving ranking without ever turning to getting offsite links and social media.
Oh dang, I cannot help but add one more point here. This is a good place to use an enticing meta description tag that appeals to the prospect of combing through legalese "Confused about blah blah blah bylaws? Call our qualified staff for no obligation assistance" -- which would you prefer to deal with -- a lifeless municipal bureaucrat or a company that offers the same professional advice for free?
NOTE TO GOOGLE: Stop changing MY meta descriptions -- YOU will NEVER know better than I do what is best served on the page results -- JUST STOP IT OK?! You tick me off. Ahhhh I feel better getting that off my mind.
No. In fact, I always open a new window every time I link to an external site. The "target" attribute has no bearing on the effectiveness of the link or how a link is treated.
I don't mind giving them a followed link. As SevenCubed said, "If they are worth linking to then they are worth doing it without restrictions." However, I don't have to let them leave my site completely should the user follow an external link. I prefer to keep my site open in the original window.