"Don't link to other sites or you'll improve their ranking. Link to mine instead" is pretty much what this site is saying. This is why Google created rel="nofollow"[1] and if you are really worried about where you pass PageRank to it is a much better alternative than linking to some random 3rd party site while passing value back to them. [1] https://support.google.com/webmasters/answer/96569?hl=en
Since the Panda update everybody should be using rel="nofollow" on all outbound links, otherwise you risk getting knocked back to page 100 should any of the sites you ever link to trip a flag that leads google to classify them as a spammer.
Don't link out to other sites using anchor text or if you've been paid to place the link and you'll be fine.
If you don't want to pass any value on to a source then why are you linking to them at all? You'll pass traffic but not authority?