Tip 1: Screen
Tip 2: Makefiles and qsub
Tip 3: find
Tip 4: svn conflicts
Tip 5: tee
Tip 6: valgrind
Tip 7: etags
Tip 8: Data Manipulation in Unix
Tip 9: gdb
Tip 10: diff and patch
Tip 11: gprof
Tip 12: Collapsing Code
Tip 13: Regular Expressions (RegEx) (also includes grep)
Tip 14: Spell check in LaTeX
Tip 15: GCC Regex Library
Tip 17: Aliases
Tip 18: SVN Externals
Tip 19: GNUplot