StarCraft II FAQs

At the time of this writing there are:

Type      Total     Russia  Taiwan   SE Asia   Europe  Korea    NA    Latin America 
 All      25,670     862     1,707    1,299     7,371  2,678  11,380       373

Broken down by Type and League (approximate numbers)

 X          1v1         2v2         3v3         4v4        2Rand        3Rand        4Rand
Diamond     700         200          50          25         200          200          100
Plat       1400         700         200          50         400          400          300
Gold       1900        1100         400         200         700          700          500
Silver     1900        1300         500         200         800          700          500
Bronze     3500        2600        1600         600        1400          800          400
Total      9400        5900        2700        1050        3500         2800         1800

This data was tabulated by myself based on the website: http://sc2ranks.com/

As to what that split represents, I refer you to this question: What percentage of players get into each league tier

One possible solution is to run (and have your friend run) StarCraft II through Steam. Steam is much less expensive to keep perpetually open than StarCraft and alerts your friends when you enter a game, even when you're not in any game.

Steam accounts are free, and it's a good place to keep all your games organized so that you have quick access to them in one place.