Automating Program Start / Stop

[Dana J. Laude]

Greetings,

How would you automatically start a program upon login to KDE and 
then stop and restart it every 4 hours?  The program in question 
is Weather Display for Linux, which has a serious memory leak. 
Normally, I just fire up Konsole and cd to wd* and 
then  ./GoWeather.sh. (memory leak due to nrComm Lib)

I assume I can do this via cron, but I've never had to do the 
shutdown / kill part before.

Thanks for any suggestions / examples!

Dana