Custom menu links in the Navigation?

Is it possible to use custom links in the navigation menu? It seems that i can only add pages from my block.

I too want an image (my logo) in the start of the navigation menu and 2 images at the end (FB and Twitter links). The images should of course be aligned the same way as the other links on the menu.

Any idea how this could be done?

Thank you in advance,

/jaze