I have a spamgourment account but I rarely use it as it's a pain in the arse to administer.
What I normally do is create an email alias which forwards to my main account. If it starts receiving too much crap I simply create another one for those who need it, delete the original and add a filter rule to deep six any incoming traffic.
I don't normally use gmail so I wasn't aware of it's 'foibles', but I may test out the livehacker trick. The problem there is it may not always work and could stop working altogether without warning.
NOTE: I am the current holder of this code. Please PM me for it.