I forgot my Apple i.d. Can i retrieve it?

I bot an Apple laptop in 2004 and registed it, but it crashed.

And I've had a Mac Mini, registered.

And now i have an iPod Touch i still need to register.

I'd like to register it under my original Apple i.d., but i can't find my records.

I still use my original email address i had then. Does that help?

Is this easy or what? Is it possible? I guess what i want to ask is: How do ye do it?

thanky u.