I like Google Alerts.
You get the latest search results (web, news, etc) emailed to you for the topic you choose.
One way that I use it is to keep an idea on what rival websites are doing. I make the search term their website address or name and see what new sites are listing their details and where they are leaving comments etc.
It’s also good to see if anyone is linking back to you or mentioning your site or anything like that.