What is claimed is:1. An open-ear headphone, comprising:an acoustic module configured to be located at least in part in a cavum conchae of an outer ear of a user and comprising: a portion that is configured to sit in a lower portion of the cavum conchae, an acoustic transducer, and a first sound-emitting opening that is configured to emit sound produced by the acoustic transducer;a battery housing configured to be located behind the outer ear and containing a battery power source; anda compliant connecting portion coupling the battery housing to the acoustic module that enables displacement of the battery housing relative to the acoustic module.2. The open-ear headphone of claim 1, wherein the first sound-emitting opening is configured to be spaced from and proximate a user's ear canal opening.3. The open-ear headphone of claim 1, further comprising a body coupled to the acoustic module and comprising a first portion configured to pass over an outer side of at least one of an anti-helix and a helix and a lobule of the outer ear, the connecting portion, and a second portion comprising the battery housing.4. The open-ear headphone of claim 3, wherein the body is generally “L”-shaped.5. The open-ear headphone of claim 4, the acoustic module and body together are generally “C”-shaped.6. The open-ear headphone of claim 3, wherein the first portion of the body is arranged at about a right angle to the acoustic module and the connecting portion is arranged at about a right angle to the first portion of the body.7. The open-ear headphone of claim 3, wherein the connecting portion is disposed between the first portion of the body and the battery housing.8. The open-ear headphone of claim 3, wherein the acoustic module and the body are parts of a unitary molded plastic housing.9. The open-ear headphone of claim 1, wherein the acoustic module has lower portion that is outwardly convex and is configured to sit in a lower concavity of a user's cavum conchae.10. The open-ear headphone of claim 1, further comprising a compliant member on at least part of the lower portion of the acoustic module.11. The open-ear headphone of claim 1, wherein the connecting portion is formed of an elastomer.12. The open-ear headphone of claim 11, wherein the elastomer has a hardness of 80 shore A.13. The open-ear headphone of claim 1, further comprising one or more external microphones.14. The open-ear headphone of claim 13, wherein the one or more microphones are configured to sense a user's voice and/or sense environmental sounds.15. The open-ear headphone of claim 13, wherein the one or more microphones are configured as feed-forward microphones of an active noise cancelation system.16. The open-ear headphone of claim 13, wherein the one or more microphones comprise a plurality of microphones which are beam-formed.17. The open-ear headphone of claim 3, wherein a center of gravity of the open-ear headphone is between the acoustic module and the body.18. The open-ear headphone of claim 17, wherein the center of gravity is configured to lie within the outer ear when the open-ear headphone is worn.19. The open-ear headphone of claim 3, wherein a center of gravity of the open-ear headphone is between the acoustic module and the body.20. The open-ear headphone of claim 3, further comprising a printed circuit board in the first portion of the body and that is electrically coupled to the battery.21. The open-ear headphone of claim 20, further comprising a flexible circuit element that electrically couples the printed circuit board to the acoustic transducer.22. The open-ear headphone of claim 3, wherein the connecting portion connects the first portion of the body to the second portion of the body and is configured to pass over an outer edge of a user's outer ear at a location of one or more of a helix, an anti-helix, and a lobule.23. The open-ear headphone of claim 3, further comprising a user interface element built into the body.24. The open-ear headphone of claim 2, wherein the acoustic module further comprises a second sound-emitting opening that is configured to be farther from the user's ear canal opening than is the first sound-emitting opening.25. The open-ear headphone of claim 24, wherein the first and second sound-emitting openings are arranged to accomplish a dipole-like acoustic pattern.
