Monster Hunter 3G makes use of the 3DS's Spot Pass functionality for a variety of wireless features. Now five days before the game's release, Capcom shared screens and details for this area of the game today.
To change the game's SpotPass settings and manage your SpotPass data, you'll want to speak to the red hatted Felyne in the harbor area. He's referred to as the Post Office.
All Monster Hunter 3G players have a guild card. It holds your character information and other bits about your hunting life. The game uses Spot Pass to exchange these with other players.
You can edit your Guild Card, adding a title (based off the titles you get when clearing certain conditions in the game), adding an introduction message, and selecting a pose and background for your character.
GUILD CARD BOX
The guild cards you receive from other players via Spot Pass are stored in the Guild Card Box, which is accessible at the post office.
The characters from the hunters with whom you've exchanged Guild Cards will appear in the harbor pub. You can pay them to complete special quests, and you'll get the rewards in return.