Do you guys know if there is a way, a tool, research, that helps finding out what are the highwest paying keywords or category of keywords for Google Adwords?
Thanks

Not for Adwords, but the following is for 7search:

http://7search.com/scripts/searchterms/top_paying.asp?n=100

I would assume the ones for Adwords are similar.

Might make sense in termos of top paying, but they pay much more on other PPCs like Overture.
The top bid for "online casino" on overture is $20 !!!

I have found a site that can provide them.

http://www.top-words.com

I have used them a couple of times and it has increased my earnings per site by about 35 %

Thanks for that Paul

No problem. There is another site that does similar -

www.affiliatehurricane.com/topkey.html

but as someone said -

"A list like that would be obsolete in short order - what people are willing to pay for clicks changes constantly"

This is why Top-Words does it for you on each request, and subsequently afterwards over a four week period. So you get 5 weeks results which are current, not something that is 6 months old.

Here are a few

High paying keywords.

asbestos lawyer $11
asbestos attourney $20

tax lawyer $15
irs lawyer $10
sarbanes oxley $14

Medical Malpractice Miami $10
criminal lawyer boston $15
dui lawyer atlanta $23

[toppayingwords.com] this website have +40.000 of the highest paying keywords and phrases.