In your friends list, your current location is listed, while in the guild list, it is not.

If you could add this to the guild list, it might cut down on the spam invitations when I am already in another "dungeon"

Most people realize, or at the very least can be taught, that it is not polite to invite someone who is already fighting somewhere. As it is now, guildies have a long list of possibilities to invite, but you can't tell if that person is chilling in Guild Hall or fighting the Snake Charmer.

Thanks