How to sync music to different iTunes?

There are songs on another computer that i want to sync to mine. Is there any way to do that WITHOUT having to erase the songs already on my iphone? Also, i've tried selecting "manually manage music and videos" and applying that setting asks me to erase and sync.

Why does my music sound So bad?

Using a pair of Sennheiser 595s on my macbook pro 13", my music sounds like utter ***. I'm not exaggerating at all. These are extremely expensive hiFi headphones and they sound like god singing in your ears when connected to my iPhone, iPod, or stereo system. However, when i try listening to music via itunes on my macbook pro, the sound is muffled, the music is distorted, static can be heard, and it just sounds HORRIBLE. I have tweaked with my EQ and tried some special presets but to no avail… WTF is going on?

Note: all of my music is 320 kbps, so the sound quality is not the issue.

How to stop an app update on an iPhone?

I was using my friend's iPhone, and saw he had a lot of app updates that weren't started, somewhere around 30. I keep my phone updated a lot, so I figured I would get them started for him. Well, we lost internet, and so they all stopped, and now, none of them are moving anywhere and he can't get on a bunch of his apps. Is there a way to cancel the updates so it will go back to normal? I know how to on the android system, but not on iphone.

Is there any Jailbreaks for ios 6.0.1?

I have an iphone 4s, ios 6.0.1 software. I know there isn't any jailbreaks that untethered but is there any at all? If there's put a link so i can download it.

Why doesn't my iPhone vibrate?

I have an iPhone 4S and I got it in July. For some reason, it doesn't vibrate! When I go to the settings to just set a vibrate tone it doesn't vibrate. It never vibrates, and I think it used to. Is there anything I can do?

What is standard int'l shipping?

I bought an item off of eBay and I'm buying it from California to Canada and I chose Standard int'l shipping. The item is the size of two iPhone charging bricks. I was just wondering would this ship to my Canada post mail box. Or my nearest Canada post service place. And also how long would it take.