These just keep getting more and more appealing. An SD card with built in wifi, geolocation tagging capability, and now the ability to post straight to Flickr (it didn’t have this before?), Twitter, and RSS feeds.
They’re still kind of spendy, though. $99 for 2GB, I think, is the current price. When larger cards (4 and 8 GB) are so cheap (less than $15, sometimes), you have to really want what the Eye-Fi cards offer. I want one, but I don’t know if I want one to the tune of a hundred bucks.