By searching the Roy Tanck's website i found these files here and here.
So the solution is download these files and upload it to your site. But blogger doesn't allow uploading javascript and swf files. So you have to signup for a googlesite. Create a google site and log-in to it. Then you can upload these files to your googlesite as:
Click MoreOptions->manage site.
Click Attachments
Then you can upload these files by clicking upload button.
suppose your googlesite name is 'mysite', then these files may be in:
http://sites.google.com/site/mysite/swfobject.js
and
http://sites.google.com/site/mysite/tagcloud.swf
Detailed step for adding tagcloud is explained as follows:
If you are not added the 'Labels' page element to your blog, add it (After logged in to your blog) by
click 'Layout', then click 'Add a gadget' in 'Pageelemtns' tab.
add a 'Lables' widget. then click 'save'
(If you already added the labels widget, skip the above step)
click 'edit html',make sure that 'Expand Widget Templates' check box is unchecked.
In your html code find "type='Label'". You can find a line like,
Replace this line by the following lines:
(you can copy the following lines by clicking 'copy to clipboard' button next to 'view source' button in the upper right corner of the first line)
<b:widget id='Label1' locked='false' title='Labels' type='Label'>
<b:includable id='main'>
<b:if cond='data:title'>
<h2><data:title/></h2>
</b:if>
<div class='widget-content'>
<script src='http://sites.google.com/site/mysite/swfobject.js' type='text/javascript'/>
<div id='flashcontent'>Blogumulus by <a href='http://www.roytanck.com/'>Roy Tanck</a> and <a href='http://www.bloggerbuster.com'>Amanda Fazani</a></div>
<script type='text/javascript'>
var so = new SWFObject("http://sites.google.com/site/mysite/tagcloud.swf", "tagcloud", "240", "300", "7", "#ffffff");
// uncomment next line to enable transparency
//so.addParam("wmode", "transparent");
so.addVariable("tcolor", "0x333333");
so.addVariable("mode", "tags");
so.addVariable("distr", "true");
so.addVariable("tspeed", "100");
so.addVariable("tagcloud", "<tags><b:loop values='data:labels' var='label'><a expr:href='data:label.url' style='12'><data:label.name/></a></b:loop></tags>");
so.addParam("allowScriptAccess", "always");
so.write("flashcontent");
</script>
<b:include name='quickedit'/>
</div>
</b:includable>
</b:widget>
Don't forget to change the location 'http://sites.google.com/site/mysite' (line 7 and 10 in the above code) to location of your site, where you uploaded the files mentioned first in this post.
For customizing and more details of this widget, look here.
