apply appropriate zebra striping to appended DOM elements with jQuery

I'm using

$(".entry").filter(":odd").addClass('alt');

within $(document).ready() to facilitate zebra striping of everything with class 'entry'.

In the course of interacting with the page, new DOM elements with class 'entry' are appended one-by-one at the end. I'd like to use something similar to the above to make sure the newly appended entry has the appropriate background color, meaning the opposite color of whatever 'entry' preceded it.

I can't think of an elegant (or really any) way to do this. Any ideas? Is there something analogous to .live() that would apply this rule to all current and future matches?

UPDATE

edit: moved update to answer

This solution isn't nearly as elegant as the CSS answers, but it does exactly what I need it to without any of the distracting side effects:

First I chain this on the tail end of the DOM append:

$('#articles').append('putyourDOMelementinhere').addClass('new');

Then I have a clumsy conditional statement to check whether the previous entry has the 'alt' class, and if it doesn't, I use .addClass('alt'). Then I clean up by plucking off the 'new' class:

 if(!$('.new').prev().hasClass('alt')){
  $('.new').addClass('alt');
 }
 $('.new').removeClass('new');

I'm sure the jQuery gurus out there could come up with a much sexier solution, but this seems to do just what I had in mind.