How to define system variable in Mac OS

Another tricky business....
We all know how to define a system variable in Mac OS we just do:

set MY_VAR=varcontent

Now the down side of this is that when you close the console ( or the tab console), or just switch tabs the variable doesn't exists any more right????


Well you are free to google the explanation for that ( is not to hard to see though).
Any way here is how you should do it if you want the variable to survive you console:

+ Go you your home path
+ With you favorite text editor change (or create) the file ".profiles"
+ In there add you variable

And presto!!!!!
From now on the variable/s listed there will be available in each console you open (only for your user of course).