I'm signed up with Alcor.

why wait until you're dead?

Several reasons:

• Suicide is usually illegal and will get you an autopsy.
• Cryopreservation techniques get better over time.
• Cryonics probably won't work, but the expected value calculation favors signing up.

Second, if indeed it's centuries before a cure for your terminal disease is found, who's going to be checking on your behalf?

The people staffing the cryo facility. You don't just toss some heads in a tank and forget about them. Constant monitoring and maintenance is necessary. You're also assuming that no friends or family sign up, and that you don't make friends with any cryonicists. And you're assuming it will always be expensive to revive people.

And when you're revived, what are you going to do in this future economy? Where are you going to live? That's a separate objection but it's one of the reasons I wouldn't want to do it.

You're talking about a society that uses nanotech or uploading to bring unproductive people back from the dead. You think it likely that life in that society would be worse than death?

PS: Your website gives me a malware warning in Google Chrome.