A link from a penalised site will not transfer a penalty to your site, be it a web 2.0, an article directory, or blog backlink. Penalties usually transition from one site to another through 301 redirects. Why? Because when a site links to you, Google assumes that the link was placed by the webmaster/owner of the site. So Google can't penalise your site because of a link you apparently have no control over.
However, when a site is redirected to another, it indicates ownership and therefore association which signals to Google that both sites are related and that the site owner is trying to manipulate the algorithm (why else would someone 301 a penalised domain to another domain?). Consequently, the penalty is transmitted to the other domain via the redirect.