Take a look at http://mbed.org/ http://mbed.org/ The supported chips are pretty powerful and a Bluetooth dongle is available. The development boards start at

Take a look at http://mbed.org/ http://mbed.org/ The supported chips are pretty powerful and a Bluetooth dongle is available. The development boards start at about $12 but can go up to $100. The bare chips from NXP themselves are $6. The LandTiger board even has a 320x240 pixel LCD touch screen display and is < $100. Amazing really.