Size and weight is a big decision factor when you are trying to find the ideal camera for your needs.
In this section, We are going to illustrate Fujifilm Real 3D W3 and Nikon D90 side-by-side from the front, back and top in their relative dimensions. Fujifilm Real 3D W3 has external dimensions of 124 x 66 x 28 mm (4.88 x 2.6 x 1.1″) and weighs 230 g (0.51 lb / 8.11 oz) (including batteries). Nikon D90 has external dimensions of 132 x 103 x 77 mm (5.2 x 4.06 x 3.03″) and weighs 703 g (1.55 lb / 24.80 oz) (including batteries).
Below you can see the front view size comparison of Fujifilm Real 3D W3 and Nikon D90. Fujifilm Real 3D W3 is clearly the smaller of the two cameras. Its body is 8mm narrower, 37mm shorter and 49mm thinner than Nikon D90. As you can tell, actually this is not a fair size comparison since Fujifilm Real 3D W3 has a built-in lens but Nikon D90 doesn't. Once you put a lens on D90, its thickness will increase significantly.
Here is the back view size comparison of Fujifilm Real 3D W3 and Nikon D90.
Weight is another important factor especially when deciding on a camera that you want to carry with you all day.
Fujifilm Real 3D W3 is significantly lighter (473g ) than the Nikon D90 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 D90, the total kit will weigh much higher.
Unfortunately neither Fujifilm FinePix Real 3D W3 nor Nikon D90 provides any type of weather sealing in their body, so you have to give extra care especially when you are shooting outdoors. If weather sealing is a must-have feature for you, check these sections: Top Compact Cameras with Weather Sealing Top DSLR Cameras with Weather Sealing
LCD Screen Size and Features
Fujifilm Real 3D W3's 3.5" LCD screen is slightly larger than Nikon D90's 3" screen.
Unfortunately, both cameras has fixed screens so they don't tilt or flip in directions.