There were many requests to have the tips categorized for easier access. You asked so here is that list. You'll notice that some tips appear in multiple categories.
This is another page you should consider bookmarking in your browser for easy access.
Tip #106. Facebook Graph Search Feature
Tip # 125 Fixing Facebook Post Mistakes
Fun Projects & Tools:
Tip #104. Push Pinning Documents
Tip #107 Pivot Tables - includes a video clip showing how it's done
Tip #108 Customizing the Quick Access Toolbar
Tip #118 Easy Excel Formatting Tips
Tip #119 Excel's Amazing Date Functions