How to make the blue arrows go away without reading every single topic

Okay, so I know the blue arrows can get annoying. They bug the hell out fo me sometimes.
And especially since you have to look at every.one.of.them. before it disappears!
So I figured I show everyone this nifty little trick. If you already know it yourself, great.

Between the Entertainment board, and the Who is Online space, there is a tiny link that
reads, 'Mark all Forums Read'. Just click it. An ta da! All the blue arrows are back to grey.