Thanks to PamiFashionDolls I've discovered and added to this blog LinkWithin, a totally free widget that 'appears under each post, linking to related stories from your blog archive. [...] The widget links to stories that are relevant and interesting to readers of a particular post, keeping them engaged with your blog, and increasing your traffic'. [end of quote]
You can also choose how many posts to display, from 3 to 5. I'm trying it since a couple of hours with 3 posts and I'm already deeply in love: it fits perfectly with my dark purple layout, it shows appealing pics and above all... it looks really cool and stylish. Get your own!