Ever balk at giving up your email address to an unseemly web site? Perhaps a "registration required" link you found over at Fleshbot? If you need to sign up for a web site with an email address, yet ...

Here’s a common hassle: You sign up for some freebie, promotion, or service that requires your e-mail address–and suddenly your inbox is deluged with ads, notifications, and other spam. Of course, ...