I don't have Google's Toolbar on my PC, so I can't tell if this is new. (Can someone verify if this is new?)
If this is a new application from Google, then the playing field just shifted in a BIG WAY in the text message space.
I saw the story on Real Tech News
Google Text Message (SMS) Give it a try. Click on the link or the screen shot.
Just remember Google is tracking all your text activity (wink wink)
The only problem with this is that you need to know the carrier of the user's phone number in order to send.
I can see a bunch of things Google can introduce with this. Notice the shift Google is making from the PC to the mobile.