Matthias Kühlke
This reminds me of a function I'd like to see, it would use the "show window names" feature.
Sometimes, if I've got many open windows on one workspace, it takes long to select the right one. If you use vimperator, you know the Quick Hints, you press a key and all the links get a label (numbers or letters) you can enter to activate that link. So I'd like to see a possibility to hit a key, then every window gets a label (something shorter than the window name), and I can press that key to focus that window.
Come to think of it, we've already got windowPromptGoto (in XMonad.Prompt.Window). That's about 95% of what I want---I'll almost always recognise the window name when I see it. (I still think it would be cool to attach the name to the window, but functionally windowPromptGoto will suffice.)