Love the plug in, use it all the time, have donated. One thing I get asked all the time is to style the "Your email" and sub/unsub buttons. I can go in and change the plug in files but these changes are lost when there is an updated. So, can you add ID tags to these fields so we can style via css.
For example (generated code)
<form method="post" action=""><input type="hidden" name="ip" value="xxx" /><p><label for="s2email" id="s2emailButton">Your email:</label><input type="text" name="email" id="s2email" value="Enter email address..." size="20" onfocus="if (this.value == 'Enter email address...') {this.value = '';}" onblur="if (this.value == '') {this.value = 'Enter email address...';}" /></p><p><input type="submit" id="s2emailButton" name="subscribe" value="Subscribe" /> <input type="submit" id="s2emailButton" name="unsubscribe" value="Unsubscribe" /></p></form>