Windows only: Whether you'd like to reassign existing shortcuts or create a whole new batch of them, Keyboard Tweaker is a free and lightweight keyboard shortcut manager.
Keyboard Tweaker include a basic set of shortcuts designed to replicate the functionality of a multimedia keyboard on a standard 101/102 key keyboard.
If you don't need those functions it's easy enough to dump them and start from scratch creating any number of keyboard shortcuts. You can create shortcuts for applications, folders, and websites using any combination of ALT, CTRL, and SHIFT plus another keyboard key. Keyboard Tweaker is freeware, Windows only.