I just saw a great tip on Steve Clayton's blog for quickly locking your Windows PC, so I just had to share. Instead of using "Windows + L" (not everyone can love the keyboard shortcuts, you know), Steve makes himself a little icon for his taskbar instead. Here's how:
1. Right-click on your desktop and select "New," then"Shortcut"
2. Paste this text in: rundll32.exe user32.dll,LockWorkStation
3. Click "Next" and type a name for the shortcut (e.g. "Lock")
4. Click "Finish"
5. You can right-click on your new shortcut and change the icon (there is a lock icon as part of the collection in %SystemRoot%\system32\SHELL32.dll)
6. Now drag the icon to your taskbar.