wireless sketch module

i would like to make a board that wirelessly connects to a computer to upload sketches but can also connect to the arduino somehow and be able to make them cheap so people can have multiple sketches at hand without multiple boards.

any opinions on this or suggestions?
tanks for any help

It would be nice to have a shield that could plug onto an Arduino (e.g. Uno R3 footprint) and work with the existing bootloader (e.g. Optiboot) to upload sketches over a wireless link, but that sounds complicated. If it was powered from the Vin pin (6V SLA, not 5V or 3.3V) I could make use of it with my Irrigation and flow measurement projects.

The Arduino BT could do this, but it has been discontinued.You can probably use a XBee for wireless comms, and the Fio is made to accept one.