1. There's an "Ubuntu Has Arrived" image that cycles through with the other advertisements on Dell's front page. This takes you to a page where you have the choice to shop for Ubuntu PC's and FreeDOS PC's.
2. The Ubuntu/FreeDOS PC's are not available through the obvious route (ie, by navigating through "Notebooks for Home and Office" -> "Inspiron" -> "Inspiron E1505", for example). There's an entirely separate navigation tree for Ubuntu orders.
3. Fortunately the navigation tree for ordering non-Windows PC's has an easy-to-remember URL:
Which is good for spreading the word the old-fashioned way.