Volumouse 2 goes 64-bit, adds per-application volume control
To start, Volumouse beta 2 adds support for Windows Vista and Windows 7 per-application volume settings. There's also a new "send hotkeys" feature which lets you use the mouse wheel to fire off custom commands to a specified application, and you can now create up to twelve rules, each with custom OSD captions.
Nir has also added native x64 support, so Volumouse 2 plays nice with both 32 and 64-bit applications.
You can download the Volumouse 2 beta from Nirsoft. It's fully portable, like so many of his other handy little programs.