You might be familiar with the Google Suggest as a free keyword research tool that is both quick and effective.
Many offer free trials of their keyword tools although you might be frustrated having to signup for free trials ect.
But another free tool that I have recently run into is called Ubersuggest – no signup forms – just get right in and use it.
Once you see your keyword you can retrieve additional “long-tail” phrases by clicking on your keyword.
Ubersuggest may not have all the bells and whistles that other keyword discovery tools have but I am really impressed by the results I have seen so far. Looks like just updated their database as well. I think it may quickly become one of my favorite keyword tools.
You may want to consider using it for your next keyword research project – I think you will be impressed!