Very good film. Julia Roberts is terrific.
It may go on for 10-15 minutes too long, but even so 'Erin Brockovich' is a fascinating biographical film. The dialogue is pretty sharp, there are a few good lines in there for Roberts. She herself is terrific here, I enjoyed her whole performance.
Away from Roberts, you have Albert Finney and Aaron Eckhart involved, as well as a few minor roles for recognisable faces from television - namely Michael Harney and Wade Williams. Finney and Eckhart are more than decent, but Roberts is most definitely the one that keeps the film moving forward.
Well worth a watch.