I was in the process of solving a problem that required me to do some message spying. I haven't used WinSight in several years, but the last time I used it, it was sufficient for my needs. Well, either the past is causing me to remember the experience more fondly (doubtful), or the environments have changed enough over the past few years to cause WinSight to not be as good any more (more likely). The current problem boils down to several windows that were not properly identified, and as a result, I could not trace messages, see window details, or simply navigate through the window hierarchy.

I installed Spy++ from VS.NET, and it worked rather well. I found what I needed with minimal fuss. Spy++ isn't a bad application, overall.

I did do some digging and found a free message spy application. I haven't tried it, but it looks promising and is billed to be better than Spy++. Check out Winspector and try it for yourself.