I keep a junk gmail account for stuff like that. I use that if I want to sign up for something that demands you give them an email address. Every few months I go in and do a mass delete.
mailinator.com is great for temporary email addresses. If someone just wants and address for verification, just give them a mailinator.com address and then check your mail. There are no passwords or security and it doesn't store mail for long, but it's perfect for one shot emails.