Disable Tooltips in Safari and Firefox
Most of the time you can solve this by hitting return or enter. The tooltip should disappear. If you want to completely disable them, it is a little bit trickier. Annoyingly, tooltips are applications specific, so you have to enable/disable them in every application. Some applications have a preference to do this. Frustratingly, many do not.
Safari has a hidden preference to do this. To disable tooltips in Safari, open up the Terminal application (in the Applications/Utilities folder) and paste the following line:
defaults write com.apple.Safari WebKitShowsURLsInToolTips 0
Then press enter. You will need to quit and reload Safari for changes to take effect. Repeat with a 1 at the end instead of a 0 to reverse this. Note that tooltips are disabled by default in Safari 3. You can use this to enable them.
If you want to disable tooltips in Firefox, start by typing
about:configinto the address bar. In the list that appears, find
browser.chrome.toolbar_tips. An easy way to find it is to start typing
browser.chrointo the filter box. Once you have found the item, double-click on it to change it from true to false. Now when you are browsing, tooltips should be disabled. Simply double-click again to change things back.