Eye-Fi WiFi SD Card Review Roundup
Eye-Fi’s WiFi-toting SD cardlooks ostensibly like the cure to the age-old “oh, the photos are all on the camera still” problem – not only does it pack 2GB of storage but can wirelessly offload all the images when it comes into range of a suitable network. The hands-on reports have been pretty favourable, too, although it would be wrong to say that Eye-Fi have scored a complete touchdown.
Blake Robinsonis probably most keen, praising the device for its low cost compared to plain old SD cards:

While Blake touches on the way that the Eye-Fi’s handles large-res images – or, more accurately, the way it treats them exactly the same as easily transferred low-res pictures – but it’s left toRyan Blockto express real concerns about how the card falls short:
“So basically Eye-Fi takes a step forward by cutting out the middleman (in this case, a USB cable to your camera, or a media reader for your vanilla SD card), but two steps back in making the assumption that you want all of the tens (or hundreds) of megs of photos on the card uploaded in full res using your camera’s batteries, and yet don’t need said photos in your photo app, not just some folder"Ryan Block, Engadget
Thing is, wireless networks are set up using the Eye-Fi website, not through any sort of interface on your camera itself, and you’re limited to secured WiFi hook-ups rather than being able to take advantage of any open cloud you might pass through. Even with 802.11g, transfers of large resolution images could – and do – take a long time, and given that there’s no ability to select which to keep and which to throw (unless you delete them prior to connecting) it could be a frustrating experience.
Overall, though, all the feedback seems reasonably positive; even Ryan throws Eye-Fi a rope by pointing out how keen he is to see the company upgrade the device and assuage some of his concerns. At $99 the opinions are split – one says buy, the other says wait – but either way Eye-Fi appears to be a qualified success.