start a script after login

I'd like to know how i can run a script after i logged in. I cannot
use runlevel because it execute scripts before login process. I want
that my script starts after login.
I'm using angstrom distribution on a beagleboard (obvisully :))

someone can give me a hints?

What does login mean; serial console, ssh, X windows?

I expect you can add something to ~/.bashrc like in any other linux distro.