To the original question; in a digital camera in format so small that a through the lens optical viewfinder is not practical, I think my favorite would be an electronic viewfinder.
However, to take of Ray's dark cloth idea, I believe that there are shade hoods for attaching to rear LCD's, and in combination with the new bigger brighter LCD's, that might work fairly well. After all, there are some advantage to two-eyed composition, as fans of the LF and MF ground glass will tell you. (I learnt that when I tried to use a video camera like a "real photographer", with one eye to the EVF, eventually giving up due to eye-strain and using the LCD.)
Finally, and off topic, with entry level DSLR kits continuing to drop in price and bulk (for example, the rumored Olympus E-500 kits), there is ever less reason for someone wishing to learn good photography to put up with the limitations of sensors 2/3" and smaller, with their hampered options for viewfinders and DOF control. Sure, get a pocket digicam as a second, super-portable option.