This blog is about how to stop a zombie invasion with the DSi.
Use 1: Take notes. myNotebook and Flipnote Studio are good uses for collecting notes. BEWARE: The notes on Flipnote Studio must be saved for safe-keeping. SD cards may be a good idea if you can carry them. myNotebook can only save to system memory and can not be uploaded to a computer like Flipnotes.
Use 2: Take pictures. Keep notes with pics, too. Take a picture of a zombie, or of evidence incase you lose it. BEWARE: Same with Flipnotes, saving to an SD card is only reasonable if you can carry them.
Use 3: Record sound bites. Record little data of sound using DSi Sound. Saving other recordings of sound onto an SD card then playing on DSi is good too. BEWARE: You can't save recordings to SD cards.
Use 4: Research. If you have Wi-Fi near an operating hotspot, do some research on the Web. BEWARE: Some data may be corrupted or fake (durrr...), so be aware.
Use 5: Give a good whack at their heads. Whack their heads off to shut them down. BEWARE: Might break your DSi and lose valuable data.
Use 6: Entertainment. Since you don't have much time for this on a hunt, maybe your spare time (most likely none). BEWARE: Don't waste time with this. It can be fatal.
Anymore? Post here.
Source: A guy who sent a letter to Nintendo Power about this, but I came up with the last 2 and the BEWAREs.