This thread has inspired me greatly. What I've been trying to achieve for over a year was the following:
LButton & Rbutton::SendInput {F13}
RButton & Lbutton::SendInput {F14}
I use these two hotkeys to pop up two floating True Launch Bar (
http://www.truelaunchbar.com) menus that conveniently allow me to access all my apps and folders from anywhere on the screen. The floating menus look like this right now (they keep evolving though):
Favorite apps and folders:
Floating Start menu:

I can drag and drop file and folders onto these menus in the same way it was possible with XP's Quick Launch, excep that True Launch Bar can be popped up at the mouse cursor and is infinitely customizable. I can't recommend it highly enough.
The above hotkeys work fine but I lose the right-click-drag functionality, which is a must in a several applications I use (e.g. secondary colour in drawing apps such as MS Paint just to name a common one).
I ended up buying a 5-button mouse and with the XButtons I was able to what I wanted and more. But I still wanted to find a solution to the above problem, and here it is:
#If GetKeyState("RButton", "p") ; !!! works on ALL next hotkeys
;Open floating Start menu - Works!!
LButton::
Goto Method_2
Method_1: ;Pops up menu after releasing RButton
SendInput {RButton Up}
SendInput {Esc}
KeyWait, Rbutton ;As soon as the RButton is released, send Esc to kill the context menu forthwith
SendInput {Esc}
IfWinExist, ahk_class TrueLaunchBarMenu
SendInput {F14} ;Close first then re-open
SendInput {F14}
Return
Method_2: ;Pops up menu immediately. Downside: if you move the mouse off TLB it does not work
SendInput {RButton Up}
SendInput {Esc}
SendInput {F14}
Sleep 100 ;Wait for menu to be displayed
MouseMove, 7, , 0, R ;Move mouse over the TLB menu because if you release the RButton while outside the TLB area you will open the Explorer context menu which is unwanted.
KeyWait, RButton ;When RButton released, TLB contect menu opens
SendInput {Esc} ;Close context menu
Return
#If GetKeyState("LButton", "p") ; !!! works on ALL next hotkeys
RButton::SendInput {F13} ;Launch floating Favourites menu
;... Other LButton & ? commands go here.
Example: Use LButton as Ctrl
c::SendInput {LButton Up}^c ;Copy
v::SendInput {LButton Up}^v ;Paste
x::SendInput {LButton Up}^x ;Cut
;... etc
#If
Obviouly I didn't include all my hotkeys in the above code but you can easily have a mouse on steroids this way. I use RButton & MButton to go back in browsers (Explorer, Firefox, IE, etc) and to undo in all other apps, MButton & RButton to go forward in browsers and to redo in all other apps. Using my 5-button mouse alone I am able to launch over 30 hotkeys. It's truly amazing.
I also have a "hot-band" along the top of my screen. Depending on where the mouse is I scroll and adjust display brightness, master volume and window transparency. No need to hold down shift. Scrolling over the taskbar switches apps.
Excuse the incredibly messy post, it's nearly 2 A.M. and English isn't my mother tongue. I just felt the urge to share my findings before going to sleep. If anyone is interested or has any questions I will be glad to provide further insight.