I really like the blue arrow at the top of a discussion page. This arrow brings me to the first post since I last arrived. (Well, ignoring the imperfection of internal anchors that you have no control over.) This has made reading Genii much easier.
I have a suggestion: make the arrow bigger. The bigger the target, the less effort it takes to hit it. Many links in web pages are quite small, like the "2" to get to the second page of a topic. With an imperfect mouse (like the trackpoint on my ThinkPad laptop) or an imperfect hand, it can be a pain to aim for the few correct pixels on the screen. But making the arrow bigger would simplify this.
Thanks for a great forum.