The URL bar on FF3 seems crowded to me sometimes, at the place where the favicons displayed just to the left of the URL bar theres a popup when you click the favicon. On most sites like TD its pretty small but if you go to this extension page on Mozilla you'll see what I mean, theres is huge and takes up loads of space in the bar
https://addons.mozilla.org/en-US/firefox/addon/8758
The reason for the waffling is this extenxsion adds a few buttons inside the URL bar to do stuff like copy the URL etc. Cant use it on mine as it says its for an older version.