What is it?
This Autohotkey script allows you to dual-cast a spell in both hands by pressing either the mouse thumb-button (Mouse 4), or pressing B. It functions exactly like the mouse buttons; hold the button down to activate both hands at once.

Features

• Doesn't mess up your typing outside Skyrim, so you can still IM and surf the web.
  
• Activates both hands with only one keypress.

Compatibility

• Skyrim (all versions)
  
• Windows 95/XP/Vista/7

Usage
Either run the desired .exe, or download http://www.autohotkey.com/ and run the included source .ahk. Running this script will launch Skyrim via the Steam Launcher if it is not already running. If you leave the game screen your keyboard will work as normal. To exit the script, right-click the Skyrim icon in your taskbar and select Exit. The script will automatically kill itself within 5 seconds of quitting Skyrim.

Changelog
v1: Initial (and final) release.

Let me at it!
http://www.desiquintans.com/downloads/Skyrim_One-Key_Dual_Cast.zip

This looks great! I'll give it a try - been looking for something like this for a while. My mouse is pretty old and tends to dislike both mouse buttons held down at the same time so I reckon this'll be really useful

i mentioned this in my other thread but i should also write it here before i forget: this is a great solution! you can also change the key you want to assign to pushing both mouse buttons down; the 'x' button felt more comfortable for me.

Wow nice, I'll try this when I get home because I've had problems with spells not getting dual casted when I click both mouse buttons sometimes and have to stop the charge and try again. Thanks for this.

Nice! This should be in the Skyrim Mods' forum though. There will be many PC users who never look at this forum but do look at the 'Mods'.