multithreading in C++

I know I've been making a lot of threads here lately, but I'm hoping this is the last one. Is there a simple way to multithread in C++? Is there a function which will split the code between threads? or would I have to switch language to do that? I'm using a pentium4 (if it helps).

Some program designs may be easier to formulate using a multithreaded approach. After all, the real world is asynchronous!

can someone give an example of this? seriously i've never written a program and thought "gee it would be better if something else was happening at the same time as this code instead of right before or after"