pg_dumpall and authentication

I'm sure you guys have heard this about 100 times, and I've done some
research on Google and found out some things, but I still have a couple
questions.

As I'm sure you may have guessed from the subject, I'm trying to
schedule (under windows) pg_dumpall to run each night/morning/full
moon/whatever. The hitch in this is that it asks for a password for each
database as it dumps it. I know I can use the PGPASS environment
variable, or a ~/.pgpass file. What I'm wondering is what's considered
'best practice' in practical applications. What solutions do you guys
use? Is it worth changing PGPASSFILE to point to a different .pgpass?

Thanks in advance for any assistance.

Thomas R. Hart II
tomhart(at)coopfed(dot)org