[aiurtourist]

I highly recommend Sneakemail.com and have been using them for over a decade. They let you set up keywords, like "foo", and then you can mail [e-mail] (or snkmail.com, since a few sites block the former domain) and it creates an alias. On the Sneakemail web UI you can enable/disable aliases and see recent mail. An alias can forward up to 5 people or so, and when someone sends you mail, if you reply you'll reply through Sneakemail.

Of course it's also worth mentioning Mailinator.com (one-off throwaway aliases, but public) and 10minutemail.com (super-disposable temporary email addresses).

[ryan-c]

I've also been using sneakemail for at least twelve years. They also let you set up addresses with a bunch of randomly generated letters/numbers that are opaquely mapped to you, but you have to log in to do that.

The only problem is that some sites ban their domains - in particular Adafruit does this (they banned existing use of it, not just new sign ups), and their support said basically "we won't whitelist your address even though you've been ordering stuff from us for over five years".

[darkstar999]

Also try 33mail.com for throwaways. You get a subdomain, so you can do [anything]@foo.33mail.com or [anything]@foo.33m.co

[pyderman]

Wow, awesome tips! Will check them out and write a follow-up