Absurdly simple DIY K-x remote timer using MP3 player. Edit: There is now a dedicated Android App for controlling your Pentax camera using this method.
Get it here: LINK (New version 1.1 with vastly improved range) [Link updated - should work now!] It is not on the Market Place because it was developed using Android AppInventor which does not (currently) allow you to upload apps to the marketplace. This BETA! Please report bugs :-) A TimeLapse Rail from BBQ rotisserie motor. Traduction.