Dougal has a good post about using post formats (new in WordPress 3.1) in themes. His technique is pretty clean, but I much prefer letting Carrington handle the conditional code.
We landed support for post formats in Carrington Core over a month ago. To support a custom post format, all you have to do is create a new template in the /content and/or /excerpt directory:
and it will be automatically used when needed.
One of the main benefits of the Carrington Core platform is that you can build themes without having to write logic in PHP. It makes creating advanced WordPress themes more accessible to designers who are still getting their feet wet on the development side.