Size and weight are big decision factors when you are trying to find the ideal camera for your needs.
In this section, we are going to illustrate the Nikon D80 and Olympus 550WP side-by-side from the front, back and top in their relative dimensions. Nikon D80 has external dimensions of 132 x 103 x 77 mm (5.2 x 4.06 x 3.03″) and weighs 668 g (1.47 lb / 23.56 oz) (including batteries). Olympus 550WP has external dimensions of 94 x 62 x 22 mm (3.7 x 2.44 x 0.87″) and weighs 167 g (0.37 lb / 5.89 oz) (including batteries).
Below you can see the front-view size comparison of the Nikon D80 and the Olympus 550WP. Olympus 550WP is clearly the smaller of the two cameras. Its body is 38mm narrower, 41mm shorter and 55mm thinner than Nikon D80. As you can tell, actually this is not a fair size comparison since Olympus 550WP has a built-in lens but Nikon D80 doesn't. Once you put a lens on D80, its thickness will increase significantly.
Now lets look at the top view comparison of Nikon D80 and Olympus 550WP.
Weight is another important factor, especially when deciding on a camera that you want to carry with you all day.
Olympus 550WP is significantly lighter (501g ) than the Nikon D80 which may become a big advantage especially on long walking trips.
Again, this comparison may not be very useful in real life as we are comparing the weight of a camera with a built-in lens to the body-only weight of an interchangeable lens camera. Once you put a lens on D80, the total kit will weigh much higher.
Weather Sealing
Thanks to the weather-sealed body of the 550WP, you can use this camera with more confidence under conditions where there is risk of exposure to water and dust compared to the D80.
LCD Screen Size and Features
Nikon D80 and Olympus 550WP's LCD screens have the same diagonal size of 2.50 inches.
Unfortunately, both cameras has fixed screens so they don't tilt or flip in directions.