Although you may resolve your question with the built in tools, I'm going to go ahead and recommend you try Captur
Captur is a simple Menu Bar interface for Mac OS X screen capture command.
Features:
- Screenshot your screen in many ways such as full screen, window, widget, selection etc
- Capture The Cursor (or not!)
- Capture The Shadow (or not!)
- Add Time and/or Date to the filename
- Specify the format (png, jpg, etc)
- Specify the folder where the screenshot is saved
And that's about it! Very simple.
I found this going through alternativeto.net but the developers website is on blogspot and I can't access that rn, so haven't been able to test. But here is the links:
Alternativeto.net: http://alternativeto.net/software/captur/?platform=mac
Blogspot: http://cambhlumbulunk.blogspot.com/p/captur.html
Couple of screenshots from Alternativeto:
In Mac OS X menu bar:

Screenshot preview with a screenshot of the settings:
