Hey guys, can i use the libraries of irRemote.h , Servo.h and newPing.h simultaneously? I've been confusing because its not compiling in arduino duemilanove. are they disable each functions? Thanks for reply 
I don't know the details of the libraries though I have used ping.h.
Each library has example sketches. Use those to find out what pins each uses, if any.
Timers are harder to find out but 2 or more libraries can't use the same timer and work.
What errors you get when compiling are probably telling you a lot.
How about you post your code in code tags or as an attachment and post your compiler errors too?