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 Pentax K10D and Pentax W80 side-by-side from the front, back and top in their relative dimensions. Pentax K10D has external dimensions of 142 x 101 x 70 mm (5.59 x 3.98 x 2.76″) and weighs 793 g (1.75 lb / 27.97 oz) (including batteries). Pentax W80 has external dimensions of 100 x 56 x 25 mm (3.94 x 2.2 x 0.98″) and weighs 156 g (0.34 lb / 5.50 oz) (including batteries).
Below you can see the front view size comparison of Pentax K10D and Pentax W80. Pentax W80 is clearly the smaller of the two cameras. Its body is 42mm narrower, 45mm shorter and 45mm thinner than Pentax K10D. As you can tell, actually this is not a fair size comparison since Pentax W80 has a built-in lens but Pentax K10D doesn't. Once you put a lens on K10D, its thickness will increase significantly.
Weight is another important factor especially when deciding on a camera that you want to carry with you all day.
Pentax W80 is significantly lighter (637g ) than the Pentax K10D 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 K10D, the total kit will weigh much higher.
Both K10D and W80 have weather sealings in their body, making them resistant to water and dust.
LCD Screen Size and Features
Pentax K10D and Pentax W80's LCD screens has the same diagonal size of 2.50".
Unfortunately, both cameras has fixed screens so they don't tilt or flip in directions.