Satisfaction Unlimited, whose Get Satisfaction online community helps customers of companies like Washington Mutual, United Airlines, Linksys, Expedia and Apple deal with customer service problems, has announced plans to release an API that will let developers add its features to other sites or applications.

"We know some of you developers out there are itching to bake Get Satisfaction into your own site, have a desire to integrate Get Satisfaction more extensively into your own customer support systems or just want to build some interesting little app on top of Get Satisfaction to make it work for you," wrote the company's Lane Becker in a blog post.

Becker noted that a beta version of the API, set for release by the end of the week, will provide access to "almost all" of the site's features.

Satisfaction Unlimited created the site to provide an online outlet for customers to air complaints and issues about companies whose goods and services they buy. For example, in December, dozens of users vented their frustrations about getting kicked off Facebook for various reasons. The site encourages the companies that are the target of complaints to engage their customers on the site. Several companies, in fact, have employees actively responding to customer issues there.

Marshall Kirkpatrick noted in a blog post at Read Write Web that the site is becoming "the hippest place for companies to engage transparently with their customers -- whether they want to or not."

While microblogging site Twitter and Hewlett-Packard's photo site Snapfish have dispatched employees to answer questions on the site, Facebook, Webshots, United Airlines and Washington Mutual haven't assigned employees to answer their user complaints there, he added.

"There are conversations going on about all of those companies on the site. I guess they prefer customers to complain among themselves," he added.

Because Satisfaction's API includes support for OAuth, an authentication protocol for publishing and interacting with protected data, Kirkpatrick noted that Satisfaction users can send their complaint thread out to friends on MySpace or GMail.

"I wonder how many of the companies absent today will be showing up soon, post-API," he added.