Playing around with Gmail this afternoon and discovered that it also supports Plus Addressing. This allows you to add a filter to your email address when handling ever you want to hand over you email address. Lets say your email address is yourusername@gmail.com and you wanted to sign-up to an Adobe news letter. The email address you might enter could be yourusername+adobenewsletter@gmail.com. Then in Gmail set up a filter/label and thats it.