Check out how ForeFathersGroup website responds. The design adjusts based on the viewport width.
The navigation menu gets isolated from the logo when the browser gets narrow, placing each menu item on its own row occupying the whole width of the screen.
Chris Coyier describes an interesting technique he noticed on Five Simple Steps website. When the browser window is narrow, the menu in the upper right converts from a regular row of links into a dropdown menu. When the user is on a small screen and clicks the dropdown menu, they’ll be able to select an option that big enough for the user to click.
Food Sense menu responds flowly from having icons on wide screens and disappears on smaller ones.
Another common technique to manage the navigation menu is using media queries to actually hide and display text based on screen size. As our flexible layout resizes, we can apply media queries at different resolution ranges to surgically correct issues as they appear – whether in a widening desktop browser window or on mobile devices.airmaxschuh Issue - Mar-19-2012