[Avalyst]

I do the same with Gmail, just add + at the end (As in [e-mail]). Of course this has the drawback of some sites being to restrictive with their checks for valid emails and not allowing the + character

[corobo]

If I were a spammer I'd loop through my email address list and strip out + and anything between it and @

[darkhorn]

Actually most of the web sites do not accept the + character.

[Avalyst]

Actually my experience is the opposite :)

[Xylakant]

The other disadvantage is that it's trivial to infer the true username from that pattern in an automated fashion.

[Avalyst]

Yep, it's not foolproof but it's better than nothing. And considering that the number of people using it aren't that many (I guess) spammers wouldn't bother