Since you're not using an optical viewfinder (unless you purchase the 17mm f/2.8 lens, which comes with an optical viewfinder than mounts in the hot shoe), you have all the normal challenges of composing on an LCD screen. To help line up the shot, I turned on the camera's Digital Level Gauge, and I don't plan on ever turning it off. It displays both pitch (vertical) and roll (horizontal) on the right and bottom of the viewfinder.
When you're off in either direction, it shows you exactly how much. When you square up the shot, the gauge lights up green letting you know you're ready to shoot. I used the leveller to capture the shot of the Brooklyn Bridge while standing on a moving water taxi. It worked great!
The LCD itself is fairly good. It packs 230,000 pixels in a three-inch area. But like all LCDs, it can be difficult to see detail when viewing in bright sunlight. And since you have the LCD on more than you would with a traditional DSLR, the battery drains quicker. I definitely recommend that you purchase an additional battery if you buy the camera.
During a full day's shoot, I had to change to the second one by mid afternoon. You can help mitigate power drain by programming the Fn button on the back to turn off the LCD (but not the camera) when you're not shooting. Press it again with your thumb, and the LCD lights up and is ready to go.
In addition to photos, the E-P1 also captures 720p video. Unfortunately, Olympus opted for the AVI Motion JPEG codec instead of a more modern MPEG-4 encoder. As a result, file size per capture is limited to 2 GBs, which plays out as 7 minutes for HD capture or 14 minutes for standard definition. (You will need a Class 6 SDHC card to assure proper performance.)
Olympus says that the AVI files were easier to play on older, less powerful computers. That may be true, but most photographers interested in this camera will likely have relatively current machines. And even though the E-P1 has excellent stereo recording via its onboard, front facing microphones, there isn't an external microphone jack. So you have little control over audio capture. If you're feeling creative, you can apply art filters to video to create motion picture effects such as grainy film or light tone.
Initially, you have two lens kits to choose from. One configuration includes your choice of body colour (silver or white) with a 14-42mm Zuiko zoom lens (above) for £610 plus VAT. Olympus is also offering a 17mm kit with optical viewfinder for £650 plus VAT (below). You can also buy either lens individually.