Script Summary: Hide search and navigation bar in Google Reader. Reclaim your vertical screen space. Toggle button allows to bring back Google bars with just one click.
Today most displays are wide or ultra-wide, with no real gain in vertical screen resolution. Horizontal tool-bars occupy the entire width, leaving just a little vertical screen space to useful application or web page data. Google is one of the worst offenders on this front.
As search bar in the Google Reader is mostly useless (the Reader doesn't preserve old posts unless you "star" them), it is the first candidate to recover screen space. Getting rid of Google Search Bar can save as much as 9% of the typical screen space.
Content panels in Reader are not expanded vertically when Google bars are hidden. My workaround is to press f twice (toggle full-screen mode).