> Maybe the sticky mail used by some other forums could
> improve the security here.

I strongly doubt that spammers will take the time to 
rebuild the original addresses using the "at", "dot" 
things. Mainly because this would generate a lots of 
garbage, require some work, and would be useless as 
millions of unprotected email addresses are already 
available (so why would they care?)

More probably scenario:

- viruses: if you sent mails to people infected (even 
temporarily), the virus collected your address in the 
existing Outlook messages (and in the "My Documents" files, 
Explorer cache, and everywhere else..) and spread itself 
using this address. From that point, it could have been 
spread to email harvesters.
Virus "authors" are now more and more linked to 
mafia/spammers groups to use trojanned machines for various 
purpose (DOS/crack attacks against competitors, spamming 
gateways, harvesting gateways, round-robin webservers used 
to sell illegal products or materials). They also probably 
have plenty of public email addresses spread among infected 
addresses to "collect" escaped addresses.

- dictionnary attacks on the server using common localized 
name/surnames

Anyway I'll try to find a better way to improve mangling of 
addresses (possibly by removing the "at"/"dot" form). But I 
still think that there is no risk with this technic - 
spammers already have more reliable ways (viruses is 
probably the best one)