The LazSolutions now has some routines for working with processes, how to list the cases opened, verify that a given process is open, kill the process, get PID from a process by name...
By combining two of the new routines, I created the function LSRunOnce, that blocks the repetition of open copies of the application.

Project home:

http://code.google.com/p/lazsolutions/

Good luck. ;)

PS. Escuse for my english.