Do you have any idea how many text messages it takes to plan a group outing for one night? Make G+ the next killer app, all you have to do is integrate it into every Android phone and tout it as an SMS replacement. Get rid of Google talk and make "Chords" something that can work outside of, but works even better with G+.
Facebook has "Messenger" but guess what, it sucks. There's no group function on mobile, it's slow to update, and often times I have to manually refresh, until my friend gets frustrated and switches to SMS. Don't make another "Messenger." BBM is the only thing besides the Blackberry brand name that is keeping RIM afloat, take a lesson there.
I'm paying $25 a month for mobile internet, $20 a month for unlimited messaging. Saving $10-20 a month by downgrading or eliminating my messaging plan because all of my friends can be reached on "Chords" would be priceless, and one hell of a selling point in this economy. Get enough people messaging on "Chords" and that becomes a reason for someone to buy an Android phone. And using "Chords" becomes a reason to use G+.
Owning the latest greatest Android phone is as much a status symbol in some circles as the iPhone, utilize it. It'd be nice to be able to see what phone my friends have, what apps they have installed and have reviewed, even what OS version. I find it ridiculous that this isn't already a feature, you track my phone and apps with my Google account, you track my friends' phone and apps with theirs. Why do I have to click a "share" button to let them know what I use and like. If I +1 an app, it should be a badge on my profile, much like Facebook's "Like feature", that links directly to the market. Hell, use the same idea for books, movies, TV shows. Put friends in the Market, and the Market on Google Plus. You have the market, you have the social network. Make it happen.
Here's a couple names for you Openfeint & Scoreloop. Chances are every Android user has heard of one or both. Chances are also good that the number of friends they have on these services hovers around zero. Cut Live and Windows Phone off at the knees and build a score tracking and achievement system into Android and integrate it into G+. Why spend so much effort on Google Plus games in the browser when you know as well as any company out there, the future is mobile.
If there's one thing Google is best at, it's integrating services in a way that makes it impossible to ignore them. Come on G+ team, WOW me.