Other great keyboard shortcuts -
1. F4 locks your references
2. ALT + ESV pastes values (add an E to transpose too)
3. CTRL + Tab cycles through open workbooks
4. ALT + NVT creates a new Pivot Table
I'm working on a new site that scores users' spreadsheet skills via short quizzes and challenges. Would love some early feedback - http://www.ratemyexcel.com