Adding activity stream (river) to a view

Hello all I am experimenting with the custom_index plugin. My idea here is to vary the content of one of the modules based on if a user is logged in. I know I can use elgg_is_logged_in() to tell if they're logged in, but I want to display, say, the last seven river events. But if they're not logged in, I'll just display some marketing text.

Is there some sort of view or function or something I can call to display the last seven or so river events to a view?

Thanks!

-Justin