How do people feel about your brand?

An interesting article at YourVersion looks at social media and looks to see how it can determine the sentiment concerning your brands. While truly gauging feelings and opinions through traditional market research methods such as focus groups are traditional, there are now thousands of online responses a minute to any given situation. How can market researchers use services such as Twitter and blogs to effectively monitor feelings on their products? Media Post has a few comments on this, read their article here.
Have you found an effective way to measure the feelings towards your brand online?