Single/Simultaneous Search Form for Blog Content and Forum Content

I'm running a blog in multisite mode using the latest versions of WordPress, BuddyPress (with BB Press integration running Sitewide forums only) and the BP-Corporate theme.

When searching using the default WordPress search form from the main blog, I'd like to search my posts/pages and sitewide forums simultaneously. How can I achieve this? Ideally, the solution would allow searching across the posts/pages from all blogs on the network as well as the sitewide forums.

Presently, the default WordPress search form doesn't include the forum threads. On the other hand, the BuddyPress search form requires you to specify a search type (members, groups, forums, blogs, posts). I can understand why a separate search function would be useful for searching for members, groups or blogs by name.

The idea is that blog posts, pages and forum threads should not be treated any differently when performing a search. The average user wouldn't make a distinction, so it wouldn't occur to them to perform separate searches for blog content and forum content.

Any suggestions?