Google software engineer Balaji Srinivasan announced in a Google+ post that the company will be rolling out a feature over the next few days that will make it easier for Google+ users to invite people to the service.

The service is still on an invitation-only basis, during what Google calls its field testing phase. Still, it has managed to get 25 million unique visitors according to recent comScore data.

The new feature addresses those times when you want to invite your friends, but don’t know their email addresses. When you click the “invite friends” link from your Google+ account, you’ll find a new link that you can send to friends via Instant message or post on the web…or on Facebook perhaps?

Some users have already indicated in the comments on Srinivasan’s post that they will post the link to Facebook as soon as it becomes available.

“Since we’re still in field trial, we’re limiting sign-ups from these links to 150 per person for now,” says Srinivasan. “We hope you’ll like this easy way to bring your friends onto Google+.”

At 150 invites per link, I have a feeling we’re going to see Google+’s member number go up pretty rapidly pretty soon. I wonder if Facebook will block the links like they did that guy’s ad.