Quick reply...
Keep computer clean of malware.
Don't use insecure Wi-Fi while entering a password.
Don't open attachments.
Forward all received spam to spam@uce.gov (I'm not sure I remember it correctly).
Disable Flash.
Use different but memorable passwords.

For instance:
on newscientist.com you have no special private information, in the worst case subscriptions can be changed. So I use: NewScientist.
Can be cracked, but it's of no use to the cracker, because I don't give any private information to this account.

I hope that possibility to see IPs of all sessions using the account and switch off all of them (with inputting password and image captcha and audio captcha) will become standard. Video captcha isn't much different from image captcha, but audio captcha IS, especially if you choose unusual language in your settings (this setting reading/writing should be guarded by audio captcha, too, so that the cracker couldn't know the language and its pronunciation).