Awesome Drop is cool.  You want to copy some files to your Android phone, but don’ t have a cable handy.  Browse for the Awesome Drop app in the Android Market.  Install it an run it.  It tells you the URL and code to enter in Chrome on your computer (it uses some HTML 5 features that are probably only in Chrome right now).  Drag your files onto the browser window, and they’re automagically transferred to your phone!