Allan Collins

Ever wanted to see your FeedBurner stats on the WordPress Dashboard? Well now you can with this simple plugin. The plugin uses FeedBurner’s Awareness API to get your feed subscriber stats directly from FeedBurner. So now you can easily check your subscriber stats from the WordPress Administration section.
-Graphing of stats from 01-01-2008 to the present.
<h3>Sidebar Widget</h3>
If you have a widget ready dynamic sidebar, you can add the FSS Widget.
Add this code: [fss_subscribers] to view the subscriber count.
You can customize how this looks for example:
There are [fss_subscribers] subscribers to this blog.
WILL DISPLAY:
There are 20 subscribers to this blog.

Feed Subscriber Stats

This plugin will show the number of subscribers according to FeedBurner/Google. Important: WordPress 2.7 and up.

viperchill

ViperBar adds an attractive bar to your site header, which you can use to increase blog or newsletter subscribers. It includes built in styling, Aweber & Feedburner integration, conversion rate tracking, split-testing, themes, and much more.
<a href="http://www.viperchill.com/" rel="nofollow ugc">ViperChill</a>, a blog on Viral Marketing, is the creator of this plugin. If you want to take your blog to the next level, you should read this post on <a href="http://www.viperchill.com/wordpress-seo/" rel="nofollow ugc">WordPress SEO</a>.
<h3>Donations</h3>
You may make donations at http://www.viperchill.com

ViperBar

ViperBar adds an attractive bar to your site header, which you can use to increase blog or newsletter subscribers.

Feed Subscriber Stats vs ViperBar