You can go to this website and click on Steve's name on the left to add a message to the Irwin family.
And, if you're interested in contributing to Wildlife Warriors (a wildlife advocacy group that the Australia Zoo sponsors), you can do that here.
Earlier this week, I ordered three Crocodile Hunter DVDs I didn't have. aurra_sing and apples491, you expressed an interest in watching some with me, so perhaps we can do that sometime soon. No specific date/time in mind, but I want to wait 'til the DVDs are here. Otherwise, I'll make you watch the movie and suffer through my impersonation ;)
Anyone else reading this is also free to join in!