I was prompted to take another look at the free (or cheepish to a point) tools you can use to monitor brands online having read a blog post by Steve Farnsworth from a year ago on this subject. There have been a number of new entrants to this space in recent months and I found that it is now possible to do some very accurate and cheap monitoring, particularly if you only receive a small amount of coverage.
It seems to make a good subject for an infographic. I have taken a couple of the more established monitoring sources like Google Alerts and Yahoo Pipes and compared them with some the more recent entrants including Mention, Social Mention and Datasift. Note, this list is obviously not exhaustive and I would be very interested in any others you think might be of interest.
I am keen to look at Social Mention in greater detail as it does not seem to have a data limit; it does alerts and RSS as well as measures for sentiment, reach, strength and passion. Their Twitter pickup looks okay although the results page features only simple filters and could make workflow CRM a bit of a challenge. It might be better to apply the API to your own dashboard or use the RSS in one of the ways described at the bottom of this infographic.