If u like getting random interesting spam like emails, this is the the best thing. You just have to join a yahoo group and see. The hard part is to find a good group, after that, its all automatic. they'll email the shit outta you. there are ones i have joined which some send me about 5 emails a day and there are some groups sending me about an email a month. They are pretty interesting, actually i love them. 
The thing with these groups is that you  dont know what will happen till you join. Well they do tell you an estimate of how many emails per day or month but there isn't a preview of emails they send. And you cant see what previous posts are either.
Even though the concept is good, there isn't a system to browse through groups. yes you can browse them like an idiot but it's not smart. Its not in a particular order. Anyways here is a link to such group.
Fun and Fun Only