What study aid have you tried so far?

Well, I got Collins cobuild dictionary with CD-Rom and Cambridge English pronouncing dictionary with CD-Rom and a software called Wordhacker.
Wordhacker is a shareware dictionary with a twist. It has American accent but other than that, not that special..
And, I've tried a number of other softwares but found them to be of little help.

My favourite bit of software would have to be the Cambridge pronouncing dictionary, I find it very useful especially when I try to find a list of words with a common sound.

Did any of you guys found anything helpful for your language learning?

Seriously, booze has helped me significantly in my learning Japanese. I got a lot of practice whilst in the pub. There's nothing wrong with a bit of Dutch courage when you're trying to learn a new language. Of course, you wouldn't call booze a kind of software ... it's more like hardware ... liquidware.

hehe I once read from somewhere (very old linguistics book) that alcohol of certain level in your blood indeed increases your ability to speak foreign language.

I've done the experiment: it works.