With this widget,
1. You can specify how many comments you want to display in your blog (defaults to 10)
2. You can specify the maximum number of letters that should be displayed in each comment (defaults to 100).
Here is how you add this widget to your blog.
Step 1: Goto Template->Edit HTML tab. Find the</head>
tag in your template and add all the code from this page before it and save the template.
Step 2: Goto Template->Page elements tab and click on "Add a page element" in your sidebar. Choose HTML/Javascript element. Give an appropriate title and copy/paste this code.
<br/><script language="javascript">
var numcomments = 10;
var numchars = 100;
</script>
<script src="http://yourblog.blogspot.com/feeds/comments/default?
alt=json-in-script&callback=commentDisplay"></script>
You need to change the blog URL to yours. You could also change the number of comments/letters per comment to whatever fits your blog. Then, save the changes and move the widget to wherever you want. There, you have a customized recent comments widget!!
For those who are interested in the details, I am displaying the content of each entry in the comment feed instead of the title (after removing all the html tags). I display only the number of characters as specified and also control the number of entries displayed. All this is done in the callback function to which the JSON object is passed.
Customizable recent comments widget (using JSON feed)
