Is it somehow possible to change the window within an application with ⌘+< (sorry, German keyboard here, I guess it's ⌘+` (?) on English keyboards) while Drag & Drop something? While it works between different applications it seems not to work within one application with multiple windows. It's especially annoying with small screens and a lot of overlapping windows.
Example 1: Mark text in browser, drag it, ⌘+TAB to terminal (mutliple windows), ⌘+< to the terminal window you want to drop the text. This works.
Example 2: Mark text in browser, drag it, try to ⌘+< to another browser window. This does not work. Same thing with drag & drop of files between two (overlapping) finder windows. It is possible to do this if you use Exposé, but that's quite slow compared to ⌘+<.
It's a really annoying thing which bugs me since years and it's still an issue with OS X 10.8.