Here’s a how-to on making a DIY Arduino Bluetooth programming shield by Joshua Newell:
If you’ve ever wished you could program your Arduino without lugging a USB cable around, wanted to put an Arduino project somewhere out-of-reach but still be able to easily upload changes to it, thought about building a project that interfaces with an Android phone, or contemplated a way to get remote sensor data streamed to your computer — this project is for you.
It uses a common, low-cost Bluetooth module mounted onto a prototyping shield for durable and reliable use. Along with the module is a circuit that allows the Arduino IDE to automatically reset the Arduino when uploading a new sketch. This project also uses the latest version of the Arduino IDE which eliminates the need to hack in modified DLL files to get the serial programming to work.