The art of the Subject Line

Noticed a few emails I've received lately have pretty useless subject lines, like "sometime..." or "Important!!!" (The latter with repeating punctuation - another peeve).  It's a bit of a skill I suppose - getting the entire gist of the email into one line.  

Here's a good subject line "Chat with Doug Cox (66 lines)" - shows me exactly what to find in that email and a hint at how long it is, in case there are several chats that would have the same subject. 

It's all in the art of naming - a tricky art.  I read once that most of good software development stems from good naming techniques.