i'm finishing up a website that'll share lists of things. would it be alright for SEO if at the bottom i had a link to paste the list, with my link included onto forums and blogs. like HTML and BBCode generated codes. or would that be considered messing with duplicate content, and not want to bother with in fear of penalization an downranking in SERPs?
Since other websites are hosting the content, the answer is that it depends upon how much surrounding content others place around the list widget and if it is enough to make that page unique. Even if there is enough content utilising a widget wuch as this with identical anchor texts pointing back to a page or site still provides virtually no value as a means of link bait.