JumiMouse Info from JumiTech.Com:

This amazing app. turns your iPhone/iPod into a fully functional mouse and
keyboard device for your PC.

Connect to your PC using Wi-Fi Edge or 3G.

Features:

~Works great with ANY software.
~Smooth and fast response.
~Automatically discovers, recognizes and remembers your PC.
~Unlimited number of PCs can be connected.
~Touch-pad with Left and right buttons
~Tapping support for Click, Double-click and Drag.
~Scroll support.
~Internal iPhone/iPod multilingual keyboard support.
~Additional Fully featured PC keyboard with all keys including symbols and function keys.
~Special shortcut keys for Select-All / Copy / Cut / Paste.
~Functions as a REAL hardware mouse and keyboard devices.
~ Works using Wi-Fi, 3G, or edge (intranet and internet).

Requirements:

~Windows XP/Vista/7.
~ The free Jumi Controller.

What's new bugfixes,

~ improved mouse response updated graphics

This Software is Free.
But if you want to unlock the Keyboard and other features, you'll need to purchase JumiMouse Plus. (less info)