Without wanting to get too bogged down in pixel peeping, I think that a scaled down image with an additional 100% crop allows for reasonable comparisons to be made, although there will be a fair bit of 'user variation'... BTW do you know what level of EXIF data the phone camera records..?
The 100% crop is showing the following in FxIF:
Camera Make: Sony Ericsson
Camera Model: K800i
Image Date: 2008:11:05 12:34:29
Flash Used: No
Exposure Time: 0.017 s (1/60)
Aperture: f/2.8
ISO equiv: 80
White Balance: Auto
Metering Mode: Spot
The K750i is the same
The W902 shows Focal Length (5.2mm) as well
FyPuNK's Nokia 6600 shows date/time only
GruB's Motorola shows "Rotate 90" only
Most others have have the EXIF data stripped out (probably by "save for web"), except for Chris S' Nokia 6300i bridge shot, which interestingly shows up as a Canon Powershot A530