In today's digital photography world, we rarely see the optical viewfinder other than the DSLR camera and some compact/system cameras.
I am a strong advocate of composing through a viewfinder rather than an lcd monitor. I believe one can engage closer with the subject matter and there is something magical about seeing your subject through the viewfinder it's the window to the world, while the lcd monitor is somewhat and electronic representation of the world you are viewing which can often be difficult to get a clear picture with constant brightness shining into your view.
However the lcd monitor does have it's place. I own a Ricoh GR Digital camera, a wonderful compact camera with an air of professionalism about it. I carry this camera with me almost all the time when I am out. It does have an option to attach an optical viewfinder to it but at the moment I am happy using the lcd monitor as I tend to shoot freely with this camera and spend little time composing but more of capturing the moment.
The optical viewfinder has been part of my visual diet since I took up photography in the good ole days... when I had a choice of taking 12. 24 or 36 shots so I had to be critical in what I photographed. The optical viewfinder is where I would had to make this decision.
Up to present day I have been through a number of digital compact cameras but have struggled using the lcd monitor to compose. However I have met my match in the Ricoh GR Digital the size and the ergonomics just feel right and I'm beginning to understand using the lcd monitor, this in turn has let to my evolution of street photography and shooting in a more 'free spirit' kind of way.
It is worth noting the recent introduction of the Fuji X100 compact camera in the market. I have come up close and personal with this camera at a recent trade show. It has a revolution hybrid viewfinder which appears to be one of the biggest selling points of the camera and it's retro styling. The camera is an object of desire but I don't think I can part with a almost four figure sum...
To conclude the optical viewfinder wins hands down but the lcd monitor does have it's place, however it's taken me around half a dozen compact cameras to finally accept this...