I dislike search boxes in browsers. I generally use Firefox for my normal web browsing nowadays, and I have a very minimalist toolbar layout without a search box:
It's nice and clean, and I normally have my browser window wider than that, so the address bar is a nice size. By default, Firefox has a lot more buttons and a search box, but I removed those things because they're useless. When I want to search, I type 'goo "rime of the ancient mariner" drink' in the address bar. I'd much rather type "goo" and a space than type my search in a special box (the default was "g" but I changed it to "goo" because I was already used to that).
In Internet Explorer 7 I can't get rid of the box:
So much wasted space. (In fairness, if I had more than one site open, Firefox would have a tab bar too, but I keep it at the bottom of the screen.) This wasn't a problem in IE6; it was customizable, and I modeled my Firefox layout after how I had IE set up. Internet Explorer does have a hidden feature that lets you do quick searches with keywords like "goo", but there's no UI to configure it (mmm, hidden registry settings), and unlike NetCaptor and Firefox, you can't set up those kinds keywords to work without a search string. For example, I have "s" set up to go to Slashdot in Firefox, but I can't do that in IE.
So, the wasted space is one irritant. But, even as great is the annoyance of having whatever I searched for last appearing in the window for all of my tabs. What if it was something embarrassing? Here are just some of the things in my actual Google search history that I probably wouldn't want to haunt me in that box...
"dragostea din tei" video
madonna "hung up" lyrics
tall quarter socks
"burst of speed" effect kotor "turn off" graphical
"tiny muffins spaced so far apart"
kitty "hair down" "glasses off" "arrested development"
annoying flash ads with close button