Rather than having an app mute my sound, I found one to deliver notifications to my computer when I am receiving a call, or a text.
Next best thing?
https://market.android.com/details?id=org.damazio.notifier&feature=search_result
Now I just need a way to have Tasker activate this app, when I need it to (it only works over WiFi, but I'm not sure what it does when WiFi is off)
EDIT (3:53pm): This app, combined with "Browsix" = A pretty great fix\solution to your "problem"...
As for the DropBox + AutoHotKey, that actually sounds like a possibility... However, I'm not a very tech-savvy person, and I won't be able to configure that setup to alter audio\itunes settings, unless I have a step-by-step guide in front of me ;p
EDIT (3:56pm):
http://www.autohotkey.com/forum/viewtopic.php?p=148405
Wow, I almost have it working! I'll post the instructions, once I am done.
EDIT (4:12pm): Ugh. I'm running in to a problem - it says to edit the autohotkey script, then save it, and wait the amount of time for it to "kick in" on your computer. The only problem is, I can't open the script on my phone (the file type is not supported). I can't even find a way to edit the script using the DropBox website, which that article says is possible to do - maybe I am missing something?
Here is the code:
Lifehacker said:
;
; Script Function:
; Controls both iTunes and Windows Media Player using hotkeys.
; Functions when maximized, minimized to taskbar, or minimized to system tray.
;
; Controls
; Play/Pause Ctrl-Shift P
;
Send, ^+p
^+p::
DetectHiddenWindows,On
ControlSend, ahk_parent, {space}, iTunes ahk_class iTunes
PostMessage, 0x111, 32808, 0,, ahk_class WMPlayerApp
return
I just need a way to edit the script file (*.ahk) remotely. So far, I am only able to edit it on my desktop and on the desktop Dropbox app - not on the website app (which, like I said, the Lifehacker article said you can edit it through the website Dropbox interface\app, but I cannot find a way to do so)
EDIT (4:17pm): Looks like it may not work, after-all
You’ll need Dropbox and AutoHotkey installed on both computers for this method.
EDIT (4:48pm): My brother is a programmer (somewhat), and I have asked him to try and work on a solution for us.

He is going to start with trying to find a way to get something in Dropbox to pause\mute your computer (Tasker would trigger the Dropbox file, which would trigger the app), and if that goes well, he will make an app for Android as-well as for your computer that will work together, and hopefully be quicker than Tasker>DropBox>Computer.
EDIT (5:19pm): Alright, so I got the Tasker task setup - It will upload the script to the folder\directory where AutoHotKey expects the script to be, in order for it to work.
It would be nice if I could get AutoHotKey to automatically play the script, when it appears (I have posted a question on the AutoHotKey forums, seeing if they can help me figure this out). If this doesn't work, then that Android Notifier app will have to do...
EDIT (5:53pm): Just realized that Tasker can\will communicate with Android Notifier (it can only enable\disable it)! Which means I am no longer going to try and get this AutoHotKey thing to work. ;p