LG Fusic / LX-550

Fusic does not have a 2.5 mm jack. But it does come with some cheap looking adapter wire that adapts a 2.5 mm headset.

There is a standard headphone jack on the right side near the hinge.

The phone comes with a stereo headphone that can be used for playing music or making phone calls.

(The phonescoop feature grid mistakenly says that this phone doesn't have a headphone jack.)

--jarandom