Add the "Call Me" widget

1. Get your Google Voice Number:
(215)-xxx-xxxx
2. Forward calls to your cell phone
2.1 Add the number
2.2 Activate the number

Adding the "Call Me" widget to my blog.
3. Go to the gear icon at the top right of the page.
3.1 Go to Voice settings.
3.2 Click the Call Widgets tab.
3.3 Click the Add a new Call Widget link.
3.4 Select the appropriate settings for your widget.
3.5 Click the Save Changes. Then, copy and paste the code in the 'Embed' field into your webpage, your blog, your auction or networking site, or anywhere you want.

Reference 1
Reference 2