Right now we only have an option for you to add a Google metatag as this is by far the most popular search engine. If the popularity of other search engines grows we may consider adding support for verifying your site with them in the future.
You can submit your site and get more information on verifying with Yahoo! by clicking on this link.
You can submit your URL to Bing here. You may also be interested in checking out this thread on our forum about Bing.