Under ‘Preferences’, you can enter a location on your profile, so you could put your zipcode there (I just did). The downside is that this isn’t searchable, so it’d be hard to compile location-specific e-mail lists from that. Another option is to create a Wiki page with the usernames and zipcodes of anyone who’d like to disclose them—that way, you’d just need to PM the relevant people to get e-mail addresses to start an e-mail group.
Under ‘Preferences’, you can enter a location on your profile, so you could put your zipcode there (I just did). The downside is that this isn’t searchable, so it’d be hard to compile location-specific e-mail lists from that. Another option is to create a Wiki page with the usernames and zipcodes of anyone who’d like to disclose them—that way, you’d just need to PM the relevant people to get e-mail addresses to start an e-mail group.