With 400 million users, Facebook is seeing 2.5 billion photos uploaded every month. Scrapblog, a startup that allows you to make beautiful Flash-based online scrapbooks, is hoping to help Facebook users make pretty collages of their photos via a new Facebook app,Share the Love.

When you first start using Share the Love, the app will employ Scrapblog’s recently launched QuickMix technology to instantly generate a photo collage with up to ten Facebook photos. The photos will be automatically arranged with a set theme, which you can change easily (Valentines themes appear to be set at the moment). Similar to Scrapblog’s online site, the app offers users coordinated stickers, backgrounds and captions. And users can easily change photos from the photos they are tagged in and from their personal albums. You can also bypass Scrapblog’s technology and start from scratch by picking a theme and choosing the photos to feature. Once you are finished designing your collage, you can publish the scrapbook to your Facebook page and photo albums.

Scrapblog is monetizing the app by offering premium content, which you can purchase through Scrapblog credits. On their first visit, new users are granted 100 credits to spend in Scrapblog’s Share the Love Marketplace, which features stickers, backgrounds and text. You can buy credits through a credit card or PayPal. And users can earn extra credits for free if they use mobile payment platform BOKU’s system. Additionally, users can earn credits by simple using the application and creating collages. The startup is also trying its hand at creating a gaming atmosphere with the app by employing a points system. By using the application and sharing collages, you can unlock various levels of the app. Each level promised exclusive content, such as premium stickers and backgrounds, with which users can customize their photo collages.

It’s wise for Scrapblog to begin to leverage the power of Facebook photos; especially considering that the startup provides a compelling technology to users. Of course, Facebook just rolled out their own slideshow feature and there are other Facebook apps, such as Photo Books, that allow users to create scrapbooks and collages from their photos.

Scrapblog, which recently brought on Jill Braff as CEO, just raised $2.5 million in series B funding from Disney’s Steamboat Ventures, bringing the startup’s total funding to $10 million. The company was first introduced back in 2006, briefly went offline, and relaunched in March 2007. The site has grown to over 2 million registered users who have created over 4.4 million Scrapblog pages.

The yfrog Twitter image-sharing service can now simultaneously post to MySpace, Twitter and Facebook. You don’t have to go to each website to share that vacation pic you took; just select your image, check the boxes for the services you want to send to and click “Post It!”

yfrog ranked eighth in our Twitter image service user poll two months ago, but it’s been putting up new features slowly over the past couple months, including the ability to post videos and images directly from your webcam. It also powers massively popular URL shortener bit.ly’s image-sharing functionality.

This is a welcome feature, but yfrog isn’t the first to offer something like this. For example, you can do pretty much the same thing with Posterous when it comes to uploading pics to Facebook, Twitter and Flickr. Posterous doesn’t advertise autopost support for MySpace, though, so we suppose you’ll make your decision about which service to use based in part on where your friends are.