via @getify. A jQuery plugin optimized to handle the use of $(this) inside an .each loop.
If you want to use HTML 5, the shiv is pretty well a requirement as Internet Explorer (up to and including IE 8) doesn't support the new elements in the spec. Plus it's easy to implement and will only be downloaded by the browsers that need it.
Dave Rupert provides an excellent breakdown of how to speed up your WordPress-powered site. There's no excuse to not spend the time implementing these changes. Even if you're like me, and have already done a lot of the work, I'm willing to bet there's a step or two that will make your site even better. For me, it's the super-duper-easy cut-and-paste improvements to the htacess file to enable gzip and browser caching.
This carousel plugin is extremely easy to implement and given the great set of options, very flexible