For the first time ever, I now have a camera without a viewfinder. Several weeks ago I purchased a TZ3. It is not my only camera, as I also have an FZ50 and still have a small DSLR outfit, although the DSLR now seems permanently locked in the closet.
The TZ3 isn't really all that bad to use. There's a Power LCD option that makes seeing the LCD outdoors very easy. This past Saturday I made a trip over to Fort Worth and had no issues seeing the LCD at all in bright light over several hours..
The bigger issue is getting used to holding a camera in a way you've never used one before and finding the way that makes it easy to compose the image and hold it still enough to get a sharp image. Fortunately, the image stabilization Panasonic uses works as advertized. What you've got to figure out is, which is more important, using mode 1 so the screen will stay still enough to make an accurate composition, or using mode 2, which activates Image Stabilization just as you take the picture.
Mode 2 is the most effective in terms of getting a sharp image...at least for me, but when you are zoomed to between 200 and 280mm, the finder can really get to jumping around due to the magnification and not being able to hold the camera to your eye, making it tough to get an exact composition you want. I sometimes have to re-shoot something once or twice to get something just like I want it. I have my LCD set up with the grid screen to aid in keeping things level, and the live histogram so I can make easy adjustments via exposure compensation to keep from blowing highlights.
I pretty much hold this camera like any other I've used, with my left hand below the lens assemby and body, being careful not to interfere with the zooming mechanism, and I hold it as close to my body as I comfortably can yet still see the LCD, making for as steady a platform as possible.
I will say this...it's a fun little camera to use, and the results can be quite good...