This instructable in combination with a free app allows you to remotely start/stop videos or time-lapse photography.
Background: We created a couple of apps that start recording wirelessly for use with our mountable iPhone case: http://www.iconic.am. We came up with this hack to start the camera from a distance.
1: the cheapest RC toy you can find (we used a $15 car from Target)
2: iPhone + iconic.am (video) or TimePress (time-lapse) app. Apps are both free and ad-free.
3: basic screwdriver set
4: soldering iron
5: hook-up wire, if you want to mount the batteries/radio away from the phone.
Step 1: Tear it apart!
Depending on the toy you use, you may want to cut off the front and back of the chassis using a hacksaw and great care to not damage anything vital.
Choose the motor based on which of the controls on the remote you want to use to activate the camera.
We chose the drive motor, which is the forward/reverse control on the remote.
Desolder the other motor or cut the leads to it as close as possible to the circuit board to eliminate the likelihood of a short.