First, flag them.
I thought about it when I read them, and my solution for the time between flagging them and a moderator deleting them is to
- delete the links, i.e. remove the hyperlink but leave the text
or
- change the links to tinyurl-previews, if their modest advertising instead of malicious spam
You can also just go ahead and delete the entire post, replacing it with (spam removed) or something like that, if you think it improves the site. I haven't encountered any spam where that seemed appropriate to me, but I'm relatively sure nobody would be upset if you did it anyway.
And lastly, this especially if you don't have the reputation to edit posts:
Go to the chat and ask someone else to do it for you
As Marco suggested, leave a comment on the post.
We're all concerned about spam and we'll all be glad to help, I dare saying. :-)
Also consider reporting the linked site to google at http://www.google.com/safebrowsing/report_badware/
- See http://www.stopbadware.org/home/badware for when this is appropriate.