Canon PowerShot D20 Digital Camera Review$349.99
Chromatic aberration is a problem on the D20. At the wide and telephoto focal settings, aberration is plainly obvious everywhere except the center of the frame. In real world terms, there's a lot of green and purple color fringing in high-contrast areas: tree branches, edges of buildings, and the like. Viewed at small sizes, it doesn't jump out, but it makes details look sloppier than they should. Aberration is actually worse from the Pentax WG-2, but the Nikon AW100 and especially Panasonic TS4 are much cleaner in this regard.
Distortion is not a problem with the D20. It's invisible to the naked eye at any focal length, unless you're specifically looking for problems.