Aside from
Pktether, there is also pkTriggercord, which is available in source, and there are binaries for Linux and Windows:
Supported cameras
Pentax K-x
Pentax K10D (Samsung GX-10)
Pentax K20D (Samsung GX-20)
Pentax istDS
Pentax K200D
Pentax K-7
Pentax K-r
Pentax K-5
Pentax K-m/K2000
Limited support
Limited support available for the following cameras:
Pentax istD
Pentax istDS2
Pentax istDL
Pentax K110D
Pentax K100D
Binary
Rpm file for Mandriva 2010.2: pktriggercord-0.77.08-1.i386.rpm
Rpms for ALT Linux can be downloaded from Sisyphus repository.
Windows (requires GTK2 ): pktriggercord-0.77.08-win.zip
pkTriggerCord