Here is a review on the Olympus E-520 Digital SLR camera from PhotogrphyBLOG. Olympus E-520 is a FourThirds system DLSR with a 10 Megapixel Live CMOS sensor and a 2.7-inch LCD screen. It features sensor-shift image stabilization, dust reduction system, Face Detection, Shadow Adjustment and the  TruePic III image processor.

PhotographyBLOG’s comments:
 So, is the Olympus E-520 the perfect camera then? Well, not quite. The viewfinder – an important part of any SLR – is just as small as the one built into the E-510. I am pretty sure Olympus could have upped its magnification by sacrificing some brightness, but they have chosen not to. Similarly, they could have put a more versatile auto-focus system into the camera – the current system is fine as regards its speed and reliability, but it could use a couple more AF sensors, preferably of the cross type.

I personally enjoyed using the E-520 very much, and doubt it would disappoint anybody who decides to buy one after careful weighing of its strengths and weaknesses. The Olympus E-520 is a camera that I can recommend to beginners and enthusiasts alike, and I would not be too surprised to see it in the hands of a few pro photographers, either.

Olympus announced the EVOLT E-520 digital SLR, which is the successor of the E-510. The Olympus E-520 is features a 10 Megapixel Live CMOS image sensor, sensor-shift image stabilization, dust reduction system, Face Detection, Shadow Adjustment, and a 2.7-inch “HyperCrystal …

This is Olympus Evolt E-420, an entry-level compact Digital SLR camera. The retro-style E-420 is one of the lightest and smallest DSLR. Olympus Evolt E-420 offers 10 Megapixel Live MOS image sensor, Live View technology, a 2.7-inch LCD screen, ISO up to 1600, and Supersonic Wave Filter for dust protection.

The E-420 is powered by Olympus TruPic III image processor. Its improved Live View now comes with contrast AF, Face Detection, Shadow Adjustment Technology & phase detection AF system. It supports both xD and CF cards.

CameraLab gives us a review on the Olympus E-510 digital SLR camera. The Olympus EVOLT E-510 features a 10 Megapixel Live MOS image sensor. With the Live MOS sensor, you can live preview the image with the 2.5-inch LCD display. The integrated image stabilizer allows you take better image even when the environment is dark.

Olympus EVOLT E-510 supports CompactFlash Type I/II, Microdrive, and xD-Picture Card.
CameraLab says:

Verdict
The Olympus E-510 is arguably the most feature-packed DSLR in its class, ticking almost every box on the wish-lists of new DSLR buyers. You get 10 Megapixels in a relatively light and compact form factor, the option of one or two decent kit lenses, and the triple whammy of built-in anti-shake, anti-dust and Live View capabilities, not to mention easy access to a wide variety of settings. It’s certainly a compelling package, especially for the asking price.

DPReview has reviewed the Olympus E-410 EVOLT digital SLR. The Olympus E-410 EVOLT features a 10 Megapixel 4/3 type Live MOS sensor, TruePic III image processor, ISO rating up to 1600. The E-410 supports the Live View which allows you to preview the image with the 2.5-inch LCD display.

The Olympus E-410 EVOLT supports both CompactFlash(Type I/II) and xD cards.

Conclusion from DPReview:
After using the E-410 for a couple of months I really grew to like it. The body itself is very light, and – when combined with the plastic-shelled (but otherwise pretty good) 28 – 84 mm equiv. kit lens – makes for a great carry-around digital SLR. We’ve become accustomed to large hand grips, but the E-410’s design works just as well; you just hold it slightly differently (ring and little finger tucked under the body). This slim design looks great but has one trade-off, the size of the battery; the PS-BLS1 may have more specified capacity than those used in the D40X and EOS 400D, but for some reason it just didn’t seem to last as long. This is perhaps down to the combination of occasional use of Live View and the control panel display, but whatever it is I had to get into the habit of putting the battery on charge every evening. …