We meet people at conferences and events all the time (just recently, at the Google Dance) who are just looking for a quick YouTube fix -- something easy to drop into their website or blog.
In the new overview page and Getting Started Guide, we highlighted simple solutions for people just looking for a little bit of YouTube, and fast. The Video Bar and Video Search Control are widgets that are easy to configure and paste into a website. The YouTube custom player, which you can hook up to user uploads and other playlists, is also an easy way to update video content on your site without changing any code.
So even if you've played around with the APIs before, now might be a good time to revisit all the things you can do! (It may be easier than you think.)