[David Lewis]

There are two popular solutions for regular WordPress (not sure how they would work with BuddyPress… I guess they would only translate the blog portion of the site). The two options are WPMU and qTranslate. WPMU make a separate post for each language while qTranslate puts all languages in one post separated by special comment tags. I found the management of a WMPU blog to be confusing. qTranslate has a simple tabbed user interface… so within your edit page for your posts… you get a tab for each language.