Ziv Gilat's Eye-Fi demo at the ProPhoto Summit today was awesome. For those who don't know, Eye-Fi is a 2GB SD card that has built-in WiFi. When I first saw it at MacWorld in January, it simply used your home WiFi network to upload pictures you shot to your computer. Now, they have a couple of other versions:
Eye-Fi Home $80 - goes to your computer only
An important limitation to be aware of about these cards is that they will only upload JPEG images via WiFi, so if you shoot RAW you will only be able to use it like a standard SD card.