I read a bunch of posts on how to pimp it, and to make things easier, I am just giving you the code for the modifications that I've made. Be sure to save your FEED ID number before you start to customize. Alternately, you can get it from your FeedBurner account.
My Old Feedburner Email Subscription Box was much wider and has a FeedBurner message at the bottom:
My New FeedBurner Email Subscription Box is more narrow:
Step 1: Cut and paste your feedburner code into a safe place.
Step 2: If you like my form, cut and paste the code below.
Step 3: Put in your Feed ID.
Step 4: Save and close
This post is by PragmaticMom. Who knew what she could manipulate HTML code?! Not really, but she can fake it when necessary.
p.s. Useful Posts on Topic:
How to Customize Your Feedburner Email Subscription Form, Part I
How to Customize The Feedburner Subscription Email Form for Your Blog