In the last few hours, the search box has taken on a new
behavior: if you click on it, the toolbar blanks out, and the
search text field expands, moving a few hundred pixels to the
left. This causes the text cursor to jump a few hundred pixels
to the left, as well.  This is—for lack of a better or more
tactful word—crazy, and it violates the principle of least
astonishment.  That is, one expects the search box to work like
nearly every other search box in existence: when one clicks on
it, it shouldn't move, it shouldn't expand, and unrelated things
shouldn't disappear.   Brandon pointed out's use of a similar
behavior for their search box, but it differs in a few ways:
• It only expands by a fraction of its original size   • It
continues to be clearly designated a search box (see update)   •
Unrelated elements don't disappear: they move slightly to
accomodate the new search box size  While still not ideal (the
text cursor moving is perhaps the worst part of this), modifying
the behavior of Stack Exchange's