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 Olympus SZ-30MR and Panasonic GF3 side-by-side from the front, back and top in their relative dimensions. Olympus SZ-30MR has external dimensions of 106 x 69 x 40 mm (4.17 x 2.72 x 1.57″) and weighs 226 g (0.50 lb / 7.97 oz) (including batteries). Panasonic GF3 has external dimensions of 108 x 67 x 32 mm (4.25 x 2.64 x 1.26″) and weighs 264 g (0.58 lb / 9.31 oz) (including batteries).
Below you can see the front view size comparison of Olympus SZ-30MR and Panasonic GF3. Panasonic GF3 is 2mm shorter and 8mm thinner than Olympus SZ-30MR but it is also 2mm wider. As you can tell, actually this is not a fair size comparison since Olympus SZ-30MR has a built-in lens but Panasonic GF3 doesn't. Once you put a lens on GF3, its thickness will increase significantly.
Now lets look at the top view comparison of Olympus SZ-30MR and Panasonic GF3.
Weight is another important factor especially when deciding on a camera that you want to carry with you all day.
Olympus SZ-30MR is significantly lighter (38g ) than the Panasonic GF3 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 GF3, the total kit will weigh much higher.
Unfortunately neither Olympus SZ-30MR nor Panasonic Lumix DMC-GF3 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 Mirrorless Cameras with Weather Sealing
LCD Screen Size and Features
Olympus SZ-30MR and Panasonic GF3's LCD screens has the same diagonal size of 3".
Unfortunately, both cameras has fixed screens so they don't tilt or flip in directions.