If tedium annoys you, and you have a good memory (or a sticky note), then you can just type 3c0 and press Alt+X. The magic 3c0 is the unicode hex number for pi. You can get this from Character Map. This trick works in many Windows text editors, including Microsoft Word and the NX Text Editor.
To get an upper-case Pi, type 3a0 instead.
In both cases, the third character is the numeral "zero" (these ar hex numbers).