Lookup element by URL I'm trying to get an element from it's URL. 

For example, say we have a url of http://craft.dev/blog/article1. Is there a function I can call within a plugin and pass over blog/article1 that will return a corresponding element, if one exists, for that specific URL? I'm sure there is a way to do this with the router, I'm just not sure what it is.
Try using ElementsService:

$entry = craft()-&gt;elements-&gt;getElementByUri( 'blog/article1' );