I don't much like the current behaviour of the front page search.  You have to hover over the magnifying glass in order to make the search box appear.  You then have to move the mouse to the search box in order to click in it so it gets focus. At the very least, hovering over the icon should focus the search box at the same time as making it appear.

A problem with having to hover over the icon to make the search box appear, is that it's not really intuitive, and distracts from the fact that the icon is also a submit button - when there's no search box displayed, it looks like a toggle but behaves like a link.  Confusing!  I think it would be better to have a search box always visible.  This way, you could click in it and start typing, which is how it should work.  The search icon would then look and behave exactly like a submit button.  I assume the search box has been hidden by default for aesthetics.  Could this be solved by having the search box displayed with a light gray background by default, that turns white when it has focus?  The gray wouldn't have to be much different to the normal grey - just enough to mark the presence of a search box.