Some tweaks for the Firefox userchrome.css file for some nice tweaks:

/* Remove Edit menu (if you already use all the keyboard shortcuts) */
#helpMenu, #edit-menu { display: none !important; }

/* Remove Back button when there’s nothing to go Back to */
#back-button[disabled="true"] { display: none; }

/* Remove Forward button when there’s nothing to go Forward to */
#forward-button[disabled="true"] { display: none; }

/* Remove Stop button when there’s nothing to Stop */
#stop-button[disabled="true"] { display: none; }

/* Remove Home button (never use it) */
#home-button { display: none; }

/* Remove Go button from address bar */
#go-button-stack, .search-go-button-stack { display: none !important; }

/*Remove magnifying glass button from search box*/
.search-go-button-stack { display: none !important; }

/* Eliminate the throbber and its annoying movement: */
#throbber-box { display: none !important; }

/* Show keyword input box when adding a bookmark */
#keywordRow { display: -moz-grid-line !important; }

/* Make the active tab wider */
tab[selected="true"] { min-width: 200px !important; }