04/29/2011, 08:51 PM
It really needs to be said that graphite powder permanently fixes the problem with getting stuck in headset mode.
Go to a hardware store, pick up a tube of graphite powder for around $3.
1) Gently squeeze a couple puffs of graphite powder into headset jack.
2) Turn phone upside down to let excess fall out.
3) Grab a pair of headphones and insert/remove them several times.
4) Enjoy your new, permanently fixed phone.
It helps to be connected to a call while doing this (I simply connected to my voicemail) so you can watch the headset icon in the lower left corner while inserting/removing the headset. When the icon switches back to the regular 'phone' icon, you're done.
After you do this, you can use headphones/headsets as much as you'd like and it shouldn't get stuck in headset mode ever again. I did this months ago and have been rampantly using headphones since then and have had no problems. And before that, the only thing that could release it from headset mode was the ghastly headset app (Q-tip with alcohol and compressed air stopped working).
P.S. All the graphite powder does is safely lube the inside of the headset jack. There is a bit inside that gets stuck, making the phone think there is a headset plugged in when there isn't. You can find graphite powder in the section of the store where they make keys, as it is commonly used to lube jammed locks.
[EDIT]: The user, jccjmml7 states in the comments below that you may try silicon lubricant as well, though I have never tested this method and can give no feedback on it's effectiveness/safety.