WP-YouTube-Lyte is a WordPress plugin that inserts "Lite YouTube Embeds" in your blog. These look and feel like normal embedded YouTube, but don't use Flash unless clicked on, thereby reducing download size & rendering time substantially. The plugin can optionally use YouTube's new experimental HTML5 embed code, meaning you can have an entirely flash-less YouTube experience on your blog.

Up to date info on WP-YouTube-Lyte can be found on blog.futtta.be, where you can also find posts about WordPress and Web Technology in general.