I am a self confessed Command Line Junkie. Here are a few tricks I use commonly that I can think off the top of my head.
These apply to both DOS and PowerShell.
1. Find a file on your hard disk - (This beats the Search doggie in Windows)
dir filename /s
2. Find a file on your hard disk without all the directory info goo -
dir filename /s/b
3. Create a list of files, say your MP3s to share with a friend? (disclaimer: don't do this piracy crap)
dir *.mp3 /b > filelist.txt
4. Find a directory -
dir dirname /s /ad
5. Move between directories easily
C:\Documents and Settings\Sahil Malik>pushd .
C:\Documents and Settings\Sahil Malik>cd \
C:\Documents and Settings\Sahil Malik>
6. Hit Tab for directory/filename completion
7. Press F7 for a previous command list. User Cursor keys to select the command you need.
8. View all environment variables
9. View only system variables that start with W
10. View a particular env. variable
11. Find what process has opened what port
12. Widen your command prompt.
13. View your TCP/IP settings.
netsh interface ip show config
14. Weird looking colors
15. Find a string in a list of files, for example "Foo" in all .cs files in your project tree:
findstr /i /s "foo" *.cs
(You might know that the windows search doggie does an awful job at search thru files, I think it just ignores files with recognized extensions, so .cs will be ignored YUK).
16. Refresh the netbios nametables: