Google Chrome 4.0 stable [Windows] has been released and supports extensions.
Google Chrome extensions
The extensions are little programs to add functionality to your web browser. The addons for Firefox is the same concept.
Visit Google Chrome extension gallery to find and install the ones that interest you.
Unlike Mozilla Firefox, install and uninstall Chrome extensions do not need to restart web browser. Great! You can view and manage the extensions settings by clicking on the “Tools” menu and select “Extensions”.