$Page — Getting the URL of a Sites Page

Nothing revolutionary here, just something I needed to find quickly and didn't appear to be obviously apparent, of course it's in the documentation etc., I just figured I'd share it too so that the answer is even easier to find.

Scenario: You're exposing some VisualForce pages over sites, and in one of those pages you want to link to another.

Solution: My first reaction was to use ApexPages.currentPage() in the controller to grab the current URL which I could then modify, but that's not the correct (or simple) approach! All you need is to utilise one of  the VisualForce Global Variables: $Page.

{!$Page.PageName}
<!-- For Example -->
<a href="{!$Page.Page2}">Link to Page 2</a>

Too easy!