OK, all of a sudden, when my mod is loaded, I get a bit of text in the notification area that says "Quest does not exist" - Now I haven't deleted or even edited any vanilla quests, and there is no such Debug.Notification() in any of my scripts...is there any way to search through the script source files to find out what script has this message in it so I can figure out what's causing it?

You can use a program like http://regain.sourceforge.net/ or http://www.fileseek.ca/ or http://code.google.com/p/dngrep/ to search C:\Program Files\Steam\steamapps\common\skyrim\Data\Scripts

I often use such a search to understand how parts of scripts work so I can use it for my own scripts. Great way to learn.

Set Windows up to search file contents in the source folder, then you can type a string and any hits will pop up quickly once indexing has done its thing.

I use http://skyrim.nexusmods.com/downloads/file.php?id=9790
Skyrim Script Dumper port from Oblivion which unpacks all the scripts into easy to view htm files and even makes 3 custom lists of all the function etc.

Awesome 3djake! Ive been needing something like what you posted. Wasn't sure where to look. That's going to help me a lot

3rd party tools are preferable, I find.

Search in Windows7 is even worse than Vista, because it appears to search for strings in an indexed folder, but doesn't necessarily report all the instances.

I've found http://www.freecommander.com/fc_downl_en.htm to be reliable, but no doubt the other tools mentioned above are good, too.

My own preference: install cygwin. Unix shell tools are great for this sort of thing.