Search for Wireless USB. There are a couple of sites that describe this, and I've experimented with it. It's still DIY stuff, but offers an affordable alternative to Canon's WFT solution.
From what I've read, they are meant to eliminate the need to hard wire the camera to the computer when download time comes. COSTCO had them a while back. I was looking into shooting teathered and looked into it but this didn't fit my needs.
Wireless USB is really designed to remove the 15ft limit between computer and printer. The current hardware requires a bulky docking station at the camera (or printer) end that makes it unsuitable for camera use without modification.
But, even with substantial DIY effort, it's still cheaper than the alternative (Canon WFT units).
HerbChong wrote:
you may note that it never made it to market.
Herb...
I'm pretty sure they did make it to market but they were discontinued shortly after being released, and when they were released, they only had a small amount of memory in them (I think no more than 256 mb).
If you are considering the Eye-Fi card, make sure you understand the limitations of the system. It has a range of 90' and is not that fast. If you are shooting a lot of images, or bursting, it will have a hard time keeping up.
If you shoot RAW, you need the PRO version.
Eye-Fi does not support the CF adaptor configuration and issues some pretty strong warnings about it.