MaskMe is a Chrome extension which helps you to maintain your security when you register with websites.
When you're setting up an account somewhere, for instance, the site will probably ask for your email address - but giving it out could result in a torrent of spam. So when you get to that point in the form, MaskMe will pop up and ask if you want to "mask" this address. Choose that option and it'll generate and enter something cryptic in the form, like "firstname.lastname@example.org", which means the site will never see your real details.
Emails sent to this new address will be forwarded to your regular account, of course, so you'll still get real messages from the site. But if you start getting spam from them, you can block individual senders with a click. Or, if there are just too many, you can turn off the forwarding of messages from that address altogether.
Sounds great to us, but MaskMe has another useful feature. When you're asked to create a logon for any site, it will pop up again and offer to generate a strong password for you. And if you accept, it'll create something like "AV.93vxZw4", enter it in the form now, then automatically complete the login whenever you return to the site in the future.
MaskMe is an excellent service: simple, effective and easy to use. If you need even more, though, a MaskMe Premium service can provide a disposable phone number, as well as syncing your account with other browsers and the MaskMe iPhone app. This costs $5 a month, and you can find out more from within MaskMe (click Home > Masked Phones).