Treasure World, as it is known now, creates a unique item for each Wi-Fi network it discovers. The items can be used to customize the character, or traded with others. There are other gameplay uses for the items, but we don't know much about the actual gameplay outside of the Wi-Fi hunting and trading.
Aspyr will open an online community that lets players interact away from the DS, allowing them to display their collections and set up trades with other players. Treasure World and its associated community will be available this summer.
[Screenshot via IGN]