I think most of us with LCD screens on the back of our DSLR or new digital compact camera know that looking at the LCD screen outside can be a real challenge, Firstly they are typically very small and more significantly they can be very hard to make out what is being displayed with the glare and reflections outside.
Somewhat by accident I discovered I already have a very cheap and easy to use, bigger LCD Screen on my camera. Ok not exactly on my camera but very easy to add. It was one of those (cheap) flat plastic magnifying lens. They are a type of Fresnel lens, a series of concentric lenses that appear as a single lens at around their focal length. I happened to have one inside a A6 sketch book in the back pocket of my camera bag, I frequently carry a small sketch book there. It isn’t exactly magic, you do need to tilt and twist and adjust the distance from the camera to get a decent view. However it is about twice the size of the screen and through a special property of the Fresnel lenses, which can capture more light at oblique angles (a feature that has made them very popular of lighthouses). There will still be glare and reflection on the lens but the image can be enriched and sharpened with appropriate tilts in the lens. The real draw back is it requires and extra hand, so works nicely with a tripod but your will have to juggle your camera in one hand and the lens in the other in most situation. Still it makes a big difference when you need to review your image in the field.
My A6 sheet lens only cosy $1.50 (from the $2 shop), but plenty of other (more expensive) forms and sizes are available from newsagents and officeworks.