PubSub LinkRanks are a useful tool that help to keep track of how different domains are being linked to by the blogosphere. They define them as:
‘LinkRanks are a measure of how many pages link to each particular site, with more weight given to fresher links and to links from a wider variety of pages.’
They help you keep track of what is hot in terms of topics/sites but are also useful for tracking your own domain.
For example they will keep track of how your domain is going over a month with a little graph. For example my livingroom.org.au domain has been pretty up and down this last month in terms of inward links and has ranked anywhere from 580th to 460th in the sites being tracked. Also helpful is their list of sites linking up to your domain.
Get a full description of how LinkRanks works here.