I've read studies that show that people can learn to memorize notes to the point where they can identify them like someone with perfect pitch would be able to, but there are still differences between that and genuine perfect pitch. Currently there's no proof that any adult has acquired genuine perfect pitch. Of course, even if it is possible to acquire perfect pitch as an adult, it's going to take you years. You might as well consider it to be like learning a second language. Even kids take years to completely get it and they're the ones who have undeveloped hearing that permits them to learn it. Don't waste your money on some guy telling you to over analyze notes and associate them with the given letters, if you want a trained ear your best bet is to make like Schmange, bust out some of your CDs and start tabbing them out yourself. All though, it would be really cool to have perfect pitch.

On a related note, I have my own question. Lately I've been transcribing midis rather than regular songs, since I can slow them down easily, and even turn off other instruments so that I can hear the given instruments better. My question is, that midis lose a certain natural tone since they're electronic. Does anyone think that will hinder my progress in ear training?