1) (read as Dude): listen, check this out.
2) (read as Duuuude): you're not gonna believe this!
3) (read as DUUUuud): what you said just really ticked me off.
4) (read as Dude Dude Dude): hot chick at nine o'clock!
*Thanks to Stephan Pastis and Rat
4) Dude Dude Dude!