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 Nikon L20 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). Nikon L20 has external dimensions of 61 x 97 x 29 mm (2.4 x 3.82 x 1.14″) and weighs 135 g (0.30 lb / 4.76 oz) (including batteries).
Below you can see the front view size comparison of Pentax K10D and Nikon L20. Nikon L20 is clearly the smaller of the two cameras. Its body is 81mm narrower, 4mm shorter and 41mm thinner than Pentax K10D. As you can tell, actually this is not a fair size comparison since Nikon L20 has a built-in lens but Pentax K10D doesn't. Once you put a lens on K10D, its thickness will increase significantly.
Here is the back view size comparison of Pentax K10D and Nikon L20.
Weight is another important factor especially when deciding on a camera that you want to carry with you all day.
Nikon L20 is significantly lighter (658g ) 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.
With its weather sealed body, we believe that K10D has a big advantage over L20 which doesn't provide any kind of environmental sealing.
LCD Screen Size and Features
Nikon L20's 3.00" LCD screen is slightly larger than Pentax K10D's 2.5" screen.
Unfortunately, both cameras has fixed screens so they don't tilt or flip in directions.