LinkAlarm is a tool that checks your site for broken links. Currently they are offering free service for the first 100 pages. It can also check your site automatically on regular basis and send you the report to your email eg. every week or every month. My WDB Project is full of links so I definetely needed this. I have also found another totally free link-checking site called Dead-Links. However the reporting format of this service is not very professional.
