I thought everyone knew of these, but after talking with some friends - maybe not. In Google's words,
Google Alerts are email updates of the latest relevant Google results (web, news, etc.) based on your choice of query or topic.
Pretty simple - here's a link to the page. Using alerts you can have Google periodically search for whatever you want to follow, and you restrict the search to just web or just video, or ask for everything. You'll get a list of links and summaries sent to you as an email, as it happens, daily, weekly - whatever you choose. I know, seems like yet another way to get more things piled up to read, but it can help to focus on some areas.
I want to look for positive online coverage of graffiti, of graffiti murals, and of graffiti legal walls, so I have set those three searches up as alerts. Then in my Gmail I have a filter that tells it to skip the Inbox with these messages and label all with "graff alerts". That way they don't clutter my Inbox and I can check whenever I want to pick the ones I'd like to share with others. And being online, check from wherever I have access.
Here's the web page where I share the links and summaries of the ones I like, maybe add a few words, using categories graffiti articles, legal wall, or mural.