"And we see that their privacy policies -- communicating about what they do and what they don't do -- is becoming very clear, either because they want to be nice to customers or because they have hired a privacy officer and the last thing they want to do is have their privacy policies interpreted by the courts," he said.

When it comes to answering e-mails, the Fortune 100 are working to be responsive. "The Fortune 100 take the attitude that 'we have thousands of e-mails coming in and we can't possibly respond to all of them,' " Golesworthy said. "But we've seen improvement in the quality of the e-mail responses."

In terms of usability, Golesworthy said the Fortune 100 sites are improving for the average user, but not for users who have visual or mobility impairments.

For site usability, Intel, Johnson & Johnson and Wells Fargo & Co. were rated highest. This area included tests for the level of support for users with disabilities. The top 100 scored an average of 6.6 out of 10 for usability.

In terms of communication and responsiveness to online inquiries, the best-rated sites were Bank of America, Hewlett-Packard Co. and Sprint Corp. The average score for all top 100 companies was just 4.9.