Blogger gives the option to use a sharing bar at a bottom of the page so that users of the blog can share the blog post they are interested in, on the various sites. This helps the blogger to drive traffic to his/her blog. However, gadget that blogger provides is a set of small bar like the one below:
This share bar is quite small. Further, we can not control its placement. And most important is..it is not attractive. We need to highlight the share bar so that people see that.
Following two are the free services that provide better sharing options.
Addthis: Easy to integrate and gives you ability to share the content on all the social websites. This helps you spread the word easily to tons of websites. It also provides in depth analysis of the traffic and audience. You get variety of sizes for the gadget.
Website : www.addthis.com
Shareaholic: I have not used this one as it does not integrate easily with blogger. We need a web host to use this. So I would simply discard this option. As such addthis works great for me. However you can find the tutorial to use Shareaholic with blogger here.