Where to buy:
http://www.ebay.de/itm/Specials-Atari-Joystick-Kaugummi-Dose-NEU-OVP-/190940922300?pt=PC_Viedeospielzubeh ör&hash=item2c74f741bc

How it looks like (there is no real indication it is only for drops....):

With the above atari joystick replica you have two choices:

1. fake bluetooth joystick ownership as it is 6,5x6,5x5,4 cm and fully working (so bending the stick looks like a real joystick and pictures do not tell it is fake

Or

2. invest some hours, add bluetooth sender modul, batterie and an arduino joystick shield including a mcu inside the joystick housing.
    On receiver side use a mcu and receiver modul. Both bluetooth modules communicates via rs232 communication to the mcu. It should be no rocket science getting both up and running in a few hours specially as both modules pairs without any intervention. This project is limited to private use at it hurts some european regulations but a real beginner project for an evening.

Attached a schematic (untested and created within 5 min). Quite easy and cheap only programming could be tricky and may contains some pitfalls.

This solution is limited to use the also provided joystick solution as both modules uses plain text communication. Default bluetooth joysticks uses USB/HID based communication requiring much more efforts.
If using a 3.3V bluetooth modul you must add additional power regulator. Any Microchip or Atmel MCU may fit (or Arduino but it is too expensive for this peanuts here)

Why is it problematic for european regulation? First it requires more CE efforts due to the used bluetooth interface, second a joystick is a device according to list and requires WEEE/CE registration anyway. You may bypass these rules for the receiver side if implemented as internal device. So finally only for private purpose or if you have some money left declare for official sale/spread. If do so remember to not deliver batteries with it else you must take them back for free (which could be quite expensive if people send them back via postage).