Google has announced via their official Google Voice Blog that they have started to allow current users to invite up to three friends to use the (mostly) free  service.

Starting today, we’re beginning to give out invitations to Google Voice users.  If you currently use Google Voice, over the next few weeks, you’ll see an “Invite a friend” link appear on the left-hand side of your inbox.

We’ll be rolling out these invitations gradually, so don’t worry if you don’t see your invitations immediately. We’re initially giving out three invites to each account, but we’re planning to provide more invitations in the future.

I’ve been using Google Voice for a while now and I am very pleased with it. One of the pros of owning a BlackBerry and being a user is the Google Voice for BlackBerry application, which makes it easier to call, SMS, view history (and more) while you’re on the run.

If you don’t have a Google Voice account yet you can sign up for one at google.com/voiceinvite, wait for a friend to invite you, or wait for me to give some away through the @BlackBerryRocks Twitter account .