Fledgling social network Google Plus will use a Fridge to continue to turn up the heat on Facebook.

Fridge — a service that allows users to create groups and invite friends for private sharing of conversations, photos, videos, and events — announced on its blog that it was acquired by Google and will be folded into Google Plus, adding that its users have until 6 p.m. eastern standard time Saturday, August 20, to download and save their data.

The company announced Tuesday that it was shutting down, saying at the time that it would delete all user data at 6 p.m. EST that day, which has obviously been extended.

Silicon Alley Insider reported that the four-person team from Fridge will initially work on Google Plus from New York, relocating to Mountain View, Calif., in August, and Fridge founder Austin Chang told SAI that while other companies expressed interest in acquiring the company, “Fridge fits perfectly into Google Plus’ plan. Right now, Google+ is asymmetric. We’re going to help them create shared spaces.”

Now the question that faces Google and Fridge: How can Google Plus Circles be integrated with Fridge’s group and sharing services?

Here’s what Fridge says on its own blog:

We are pleased to announce that the Fridge team will be joining Google!

It has been an amazing ride developing Fridge, but most important, we are very thankful to our enthusiastic community of users. We strongly believe in the group social experience, and we couldn’t think of a better place to realize our vision of bringing the nuance and richness of real-life sharing to the Web than as part of the Google Plus Project.

Fridge is closing up shop — the team will be folded into Google Plus, where we’ll continue some of our efforts. We heard you loud and clear over the weekend, so we’re expanding the time during which your Fridge data will be available for offloading. While you will no longer be able to post anything new to Fridge, you will still be able to download and save your data until Saturday, Aug. 20, at 6 p.m. EST. After that, in accordance with our privacy policy, we will delete all user data.

We look forward to continuing the vision of creating fresh and exciting social group experiences for users across the web.

Keep on keeping it fresh from Team Fridge, and see you on Google Plus.

Presumably Fridge will enable the formation of groups on Google Plus, bringing that social network up to speed with what Facebook already offers in the way of group chat and content sharing.

Readers: Do you think the potential combination of Fridge’s technology and Google Plus Circles present a threat to Facebook?