New version of the n64 emu for Xbox:

This replaces the default.xbe in Surreal64(info) XXX B5 with one that supports launching a ROM using a command line parameter.

The patch comes in two versions.
* Version 1 will allow you to choose which emulator and video plugin you wish to use before the game launches.
* Version 2 will launch directly into the game without any prompts.

http://forums.xbox-scene.com/index.php?showtopic=679077