With the Sporadic-E season started, I've been looking for ways to be alerted whenever there is an opening. It's all very well to say "real amateurs tune the bands" but although I'm at home most of the time and well placed to take advantage of band openings, I'm usually busy working or doing something else and don't have time to spend endlessly tuning the receiver.
So I was pleased to discover DX Sherlock, a system operated by VHFDX.net. This is a set of maps for each of the bands, 10m and up, that shows contacts which have been reported to its DX Cluster. These contacts are plotted on the map, and easily show the position of any Sporadic-E clouds, as you can see in the example.
Another nice thing about this site is that you can have email alerts of Sporadic-E, tropo and other propagation events on the bands you are interested in sent to your mailbox. If you are interested in the higher frequency bands, this site is well worth a visit.