Plugin to add an extra loop (or 2) before the main loop

I’m working on a plugin to add an extra loop or 2 (for featured posts, etc) above the main loop.

I’ve tried hooking into loop_start, but the main loop is already started by the time it is triggered and this causes problems (not to mention the infinite recursion when the inner loop triggers loop_start 8=)

What actions can I look at to get my loop put in the right place? I need wp_query to be run so that I know what the page type is (i.e. is_home() needs to work properly).

I want this to work with any theme that uses a standard loop for the home page.