This has been going on a while, but now that the K-3 is supposed to be compatible, I am interested in this.
I just called my local radio shack today and they have one, which I asked them to put on hold. So you can still find them.
In Store Availability
you can check your local store inventory here. it's not terribly accurate, so if you are very interested, visit the store. or call?
Eye-Fi™ 4GB SD Card + Wi-Fi®
Model: Eye-Fi4CN | Catalog #: 44-268
it's on clearance for $10.48, and for comparison, it's $27-37 on amazon, depending on the seller.