The recent discussions about how strict aggregators should be when reading invalid or ill formed feeds (e.g. RSS or Atom) brought to mind an idea: an automatic service that checks your feed for validity and send e-mail whenever it finds a problem. The service would be an aide to web site authors, alerting them to any problems with their RSS/Atom feeds. Rather than authors manually checking their feeds with the feed validator, the service would do this for them automatically. Rough thoughts on some of the details: Web front-end for sign-up, including feed URL, e-mail address, and frequency of checking…