I have seen some custom made gadget for the dashboard and a plugin in admin-mode in EPiServer 6 R2 that will let you rebuild the search index. 

What options are there in EPiServer 7?

Are there any official plugin-in/gadgets or some other built-in feature that I have yet to discover?

Is it possible to manually rebuild the entire index without any gadgets/plugins? how?

What is the most common method?