WASHINGTON?Facebook launched a trial version on Wednesday of a much-anticipated new service which allows members to pose questions to other users of the 500-million-strong social network.

"Facebook Questions," as the beta, or test, product is called, lets members "tap into the collective knowledge" of other members, Facebook's director of product management Blake Ross said.

Ross noted that Facebook members routinely pose questions to their network of Facebook friends.

"With this new application, you can get a broader set of answers and learn valuable information from people knowledgeable on a range of topics," he said in a blog post.

"For example, if you're vacationing in Costa Rica and want to know the best places to surf, you can use Facebook Questions to get answers from nearby surfing enthusiasts," he said.

"Because questions will also appear to your friends and their friends, you'll receive answers that are more personalized to you," Ross said.

Ross said Facebook Questions is currently only available to a limited number of members but "we'll be developing it rapidly based on their feedback."

Select members will see an "Ask Question" button at the top of their homepage, Ross said, and questions and answers posted using the questions application will be "public and visible to everyone on the Internet."

Questions can be tagged with a specific topic, "Photography" or "Cycling," for example, and "will be shown to people who have expressed interest in the particular topics you tag, as well as to your friends and friends of friends."

Facebook's new questions product is similar to services offered by other Web companies, including search engine Ask.com, which announced on Tuesday that Ask users could have questions answered by other human beings.

Google earlier this year bought Aardvark, a "social search" service that relies on a user's social network contacts ? including their Facebook contacts ? to provide answers to questions.

Yahoo! has a similar service called Yahoo! Answers and a startup called Quora provides answers to questions submitted by other users.