You can now answer your Gizmo5, Google Voice and other calls directly from Gmail by adding the GizmoCall widget to the left side bar.
Here's how to set it up: Login to your Gmail account, then click on the Settings tab, and the Labs tab. Scroll down to 'Add any gadget by URL' and click Enable
Go back to Settings, click on the Gadgets tab & paste in the following URL http://hosting.gmodules.com/ig/gadgets/file/103368509318653270970/gizmo5.xml
You'll now see a Flash phone embedded on the left side bar, which will ring whenever you get a call. Click the green button to answer the call and the red button to hang up. Use the sliders at the bottom to adjust your volume and mic level.
It's recommended that you hook up a headset to your computer, and if you'd like to place a test call, dial 411 which will ring Google411.