Spell-check your code

I find it amusing when I stumble on mis-spelled API functions and structures. The irony is that a gaffe by one programmer becomes a documented interface, and it's often impossible to correct the mistake.

Take for example the PrintProvidor entries in Win32:
http://msdn.microsoft.com/en-us/library/aa506097.aspx

Luckily the person writing the surrounding text was able to use the phrase "print provider".