When I do command+shift+4 to do a screen capture, can I specify a folder for these to land in or must they all land on my desktop? I take a ton of these and my desktop gets cluttered fast!
They land on the desktop, but you could create a folder for them and put an alias for that folder in your dock...then just drag them to that folder every so often.
You can use defaults write from terminal to change the save location (and the file format if you're so inclined) or else you can download this script and use it to do this.
The script is point-and-click, for what it's worth. But you're certainly not obligated to use it. And the defaults it writes to are completely legitimate. They're there for this purpose and this purpose only.