Preferences → Under the Hood → Clear Browsing Data → Select the time frame and check only “Delete cookies and other site and plug-in data” → Clear Browsing Data

Tools → Clear Recent History → Select time frame from the dropdown menu(if you wish all cookies removed - select Everything) → Mark Cookies only → Clear Now

Settings → Configure Konqueror → Cookies → Management → Delete all

Tools → Internet Options → General → Delete Cookies (under the Temporary Internet Files section)

Tools → Delete Private Data → Details → Mark Cookies only → Delete

Safari → Preferences → Security → Security tab → Show Cookies → Remove All