What services/apps can cause my iPod to be remotely wiped?
The remote wipe is part of Apple's own code - so any program that wants access to that API has to work with Apple to ensure it follows Apple's policies of not surprising end users.

This feature is well documented in the enterprise documentation as well as part of MobileMe Find My iPhone terms of service.

The things that currently will wipe an iOS4 device: (the first two depend on physical posession of the device - the second two require some sort of data connection to the Apple (or Exchange) servers.


Restore the device over USB (in recovery mode if a passcode prevents normal restore)
Turn on the failed passcode erase trigger and enter the code wrongly until the erase threshold is passed
Turn on Find My Phone and activate an erase through another device using Apple's push data servers.
Turn on Exchange remote wipe and activate it through the Exchange server's push data service.


I don't know of any apps that have hacked this interface. Ones in the App store would likely get caught before they shipped. Ones in cydia or jailbreak community might be more prevalent, but I'm not familiar enough to say if there are any in the wild so I'll leave that for someone else to answer here via an edit or in another answer.