Are there any really good methods of developing your ear. Like if you hear an intro to a song and can tab it out within 10min or so or figuring out the key and progressions used etc.... How long does it take to actually do that anyway?
playing by ear is something that isn't learned so much as picked up without you realizing you can do it... I know because thats how things have kinda gone with me, and as long as its nothing to rediculously hard, I can play it by ear, especially classical for some odd reason
1966 rickenbacker fireglo 335
78' twin reverb (loud awesome tone)

practice makes practice... never perfect
It's a very harsh learning curve and takes years to be able to do well at all.

To start off with just try picking out the main melodies to TV themes and stuff; they're usually quite simple and repeated a lot so it's easy to just guess.

Another thing you can do is try and learn theory well; once you know keys and scales you can guess pretty accurately where all the notes in a melody might be, you just have to get them in the right order.
R.I.P. My Signature. Lost to us in the great Signature Massacre of 2014.

Quote by Master Foo
“A man who mistakes secrets for knowledge is like a man who, seeking light, hugs a candle so closely that he smothers it and burns his hand.”

It comes with time. I have a friend who asked me what a song was one day, and he played part of the intro to 'Crazy On You'. He said he heard it on a commercial two or three times. So some people pick those things up a lot quicker.
All your base are belong to us.
All your base are belong to us.
All your base are belong to us.
All your base are belong to us.
You'll get it eventually. Just keep listening to music and trying to figure it out. You know when I realized I was getting better? I had just restrung my guitar, stretched out the strings, and tightened them. Walked into my room to plug into my tuner and to my surprise the strings were already within like 10 cents of being perfectly tuned. I just did it without even thinking about it.