Cut up your music. Makes for a more compact trailer.

[Nosedagger]

Examples of music that has been cut up(Search on youtube):
Axium Trailer
Portal Trailer
Half-Life 2 Episode II Teaser Trailer
Half-Life 2 Episode I Trailer
Half-Life 2 Trailer
GTA IV Trailer "Move up, Ladies"
GTA IV Trailer "Special Someone"

Examples of trailers with multiple music pieces used(to reflect mood change):
Star Wars Prequel Trilogy Trailers (The Extended/Theatrical ones are best)
Serenity Theatrical Trailer

However, if you prefer to use full-length music tracks:
Pistol Ninja Shards of Fury Trailer
All MAIET-made GunZ trailers (even the old ones)
Terminal Velocity
Team Fortress 2 Extended Trailer (the one where they show multiple classes in action)

Trailers that don't use music, or only use it minimally:
Some Bioshock trailers
Cloverfield Trailer

The first group usually works better for teaser trailers (trailers under a minute or so), while the second works well for stuff above that. I don't have much experience with the third or fourth group.