Google Voice seems to be another great to communicate to people via single google number to make calls, read voice mails and much more. Right now google voice is being available to US citizens only but they seem to be rolling out soon in other countries too. You can do much more with google voice, get an overview of features here
GVDialer is a free windows based application which runs in system tray does not consume much resources and still provide access to useful features and advantages to google voice users
1. Easily place voice calls and send SMS messages
2. Fast access to contacts and recently used numbers
3. Runs independent of internet browser
You can also easily send sms using google voice with this application as shown in the snapshot below.
In all this seems to pretty useful application which can help you google voice more effectively in a easy way without requiring you to open google voice in browser.