This post is hitting people where they live, apparently-- so I have a bit to add:
I can't stress enough to anyone who reads this -- address these issues now while your parents are healthy. Granted, it's not easy, but putting it off can be far worse.
Speak to a lawyer or a funeral director and find out the laws in your state so you can avoid the [luckily, fairly minor] obstacle my family is facing.
I am so grateful we communicated as much as we did a number of years ago. My mother and I [and later, she and my sister] discussed the fact that she wanted a Do Not Resuscitate Order and hospice care when the time came to let go.
Now that that time is here and we can't ask her what she wants, it's such a relief to know we're doing what she would do for herself if she were cognizant.
fwiw -- My discussion with my mother was prompted by the fact that I took my own living will to my parents' home and asked them to file it away for me. That naturally led them to discuss the issue with me. It made the situation far less awkward than if I had just jumped into the matter with them. I didn't plan it that way, it just happened -- but it's certainly one approach that can be used consciously.
Granted, it would be far easier to file the cremation paperwork ahead of time-- but that is a minor matter compared to knowing her wishes regarding resuscitation, hospice and end-of-life-care. And the fact that all four of us know that she made plans, years ago, to be cremated will make that merely a formality when the time comes.
Another thing I began doing a number of years ago was addressing with my sister [who lives on the other side of the country] and my cousin [who is a nurse and lives about 30 minutes from my home] what my wishes are. I brought up the matters to them-- and spared them the embarrassment of asking me about them.
I carry my cousin's contact information in my billfold so he can be reached in case of emergency. I also keep written instructions in my purse [and wear a homemade 'dog tag' under my shirt] so that hospital personnel won't place me on machines before contacting him. Just a few ideas to consider.