Well I didn't know about this tools but they seem to be preety useful, I guess I'm gonna try Wordtracker, is it free BTW >?
WT is a paid tool but there is a free option you can use for individual queries.
This free WT option also ties to Google Trends for additional data.
Google Trends & Wordtracker mashup | GTrends
And here's the free external Google Adwords keyword tool too.
https://adwords.google.com/select/KeywordToolExternal