On the Makerbot Operator's Group there was a discussion on network control of the Makerbot. A few options were discussed, including the EyeFi and the Toshiba FlashAir.
I decided to buy a FlashAir and see if I could get it to work. The ability to both download from and upload to the card is listed as a feature, and mentioned in many reviews. Unfortunately, there is no mention of the upload feature in the documentation or in the card's UI.
Out of the box, the card broadcasts as a WiFi base station. When you connect to the card's SSID, you then get a web server that allows you to read the files on the card. That's about it. Settings are configured by a text file stored in a directory on the SD card.
Luckily, it seems like there is a trove of undocumented features on the card, including upload ability, and the ability to join an existing network. I posted to the Google Group with some information on how to use this card in a Makerbot. I've found a lot of information, so rather than multiple posts to the Google Group, I figured I'd post the info here.