I read about Listable this morning on Online Tech Tips, and it sounded like an okay premise. It's basically a website which draws on social search/bookmarking principles to compile lists of online resources. We know that members of online communities will voluntarily create lists - Amazon is a classic example.
Unfortunately when I went to Listable to have a look around, it seems to have fallen prey to a bunch of porn and credit card shysters - every second 'list' seems to be pushing porn or how to get out of a bad credit rating. You need to create an account on the site in order to create a list there, but obviously they need to put a few more controls in place if they want the site to work.
While the links identify the user who submitted them, there doesn't seem to be any mechanism ensuring that links are relevant to the list topic - I found a listing for 'personalised dog tags' in the "Resources for Wedding Planning" list.
A barometer for contributor credibility is also going to be necessary - I'd want to know whether someone who has created a list is a genuine user rather than someone promoting their own business - so a flag showing the number of lists they've created or number of "votes" they've received as a useful contributor would be helpful.
In short, nice idea, but right now it's just an example of how not to run a social recommendation site. Shame.