You might enjoy this "position:fixed fixer" bookmarklet I wrote, it just sets all elements with position:fixed to position:static. In 99% of the cases this does
exactly what is needed to improve the page, without even having to manually click or select the elements.
javascript:for(var a=document.querySelectorAll('*'),i=0,e; e=a[i]; i++) if (e.currentStyle.position == 'fixed') e.style.position = 'static'; void(0)
I have it named "fix", so I can just type "fix" in the address bar and it applies to the current page. It's lovely, all those floating fixed elements just disappear (possibly somewhere to the bottom of the page) and you get your screen estate back.
edit: I just see a bunch of others also made bookmarklets to remove elements, so I added a bit more description as to why mine is different. Setting all position:fixed elements to position:static really does seem to do exactly what you want in one fell swoop, in 99% of the cases.