Is there an alt-tab replacement for windows that works in the same manner as command-tab and command-tick on OS X?

example of what I'd like to do:

If I hit alt-tab, I'd like to switch between open applications, rather than all windows currently open. If I hit alt-tick, I'd like to switch between open windows of the same application.

VistaSwitcher is almost there, in that it allows you to alt-tick switch between windows of the same app. So if I have 4 firefox windows open and one of them is my active window, I can alt-tick to switch between those 4 while ignoring any other open apps. However, VistaSwitcher's alt-tab functionality is similar to stock Windows alt-tab, where you cycle through all open windows, regardless of whether there are multiple instances of certain applications.