GButts is a Firefox add-on that lets you access all Google service on your browser just with a click, you need not to visit the site by typing the URL or bookmark the service.
Just install the plug-in and drag the GButts Toolbar to your navigation bar or menu bar from ‘View – Tool bars – Customize.
You can change the main appearance from a Toolbar with all buttons you've selected to a single Dropdown Menu from settings. You can also enable or disable any services from settings.
This add-on supports Firefox 2 – 3.5 and can be install from Mozilla Add-ons.