The forums keep track of what topic's have posts I haven't read yet, and there's the last post button to take me to the bottom of the topic. The Arstechnica forums go a step further and will take you to the last post in a topic that you haven't read yet. It was a fairly recent change, and until it was added I never felt its lack. Now, in this forum, I do =( Something to consider for a future upgrade.
Click the blue "New" button next to the topic title. But yes, I've seen other forums that put a "Go to newest post" at the top of every page.
D'oh! Never thought to click on the little 'new' image. Perfect. Thanks!