Admin menu - how to add favourites links?

I would like to add my own favourites to the Administration Menu. One way to do it is described here: http://blog.urbaninsight.com/comment/95
But this method creates just another option in the menu, when you click on it, the current page changes to the one specified in the option.

What I would like to do is to have something similar to what happens when you hover the mouse over the arrow-up-triangle on the far right side of Administration Menu (to the right of Log out). After hovering, there appear two options: "Add new content" and "Find content". It looks like a submenu which expands not downwards, but to the left. After clicking on them, the current page does not change - instead, administration overlay is displayed with specific task.

So I'd like to add options to this submenu - maybe programmatically in my module - how to do it?

Last but not least, is it possible to have both Administration Menu visible at the top and also the core Drupal Favourites bar visible? That's because the standard Drupal Favourites bar makes it very easy to add a favourite, just click on a "+" button on the overlay. (but the drawback is that it permanently takes space, so I'd prefare the previous option with mouse hover submenu)