Exectution on the stack

[arnix]

I've listened that it's possible to overcome the restriction in WinXP SP2
which does not allow to execute commands on the stack. i have 2 questions:

1. how can i do that in XP SP2 (or maybe in other OS too?) (i know google.com but maybe someone has a small and good way to do that)

2. i wanna write a simple protector (just for experience), what do you
think, is it a good idea using this trick (execution on the stack)
or it is a outdated trick and it will not be possible to overcome
the restriction on newer OS-s with new processors.

thank you.