According to the instruction manual for ExciteTruck, the game "allows you to listen to your personal MP3 music files during the game. By inserting an SD Card into your Wii console, you can choose the music you want to hear."
Nintendo has previously hinted at the Wii's MP3 playback capabilities as a feature in the Wii's photo channel, allowing players to view a media slideshow with their custom MP3s playing in the background.
Nintendo has yet to clarify which SD cards will work on Wii other than their own re-branded San Disk cards. Most SD-capable devices support any brand of SD card, excluding some digital cameras that require a faster SD card to store digital video on the fly. It is not expected that the Wii's storage and playback functions will require these faster cards.
SD cards can hold up to several hundred songs, or several thousand photos, depending on the amount of memory per card. Wii-compatible SD cards can hold music, photos, game files and video to be played on the Wii. For more information on SD cards, visit http://www.sdcard.org.
The Wiire will keep you updated on Wii's media functionality.
