301 redirection-is it good or bad?

[blackpower]

Hello,
I want to ask you to share the experience, does multiple 301 redirection to the main site hurts rankings Or is it beneficial?
My experience with -1-2 keyword domains redirected shows that it helps with ranking main site for the keyword in the domain redirected; But I never really tried redirecting say 100-200 domains (many with irrelevant keyword but geo/lang relevant) at once for traffic.
Comments appreciated

[blackpower]

ok, since nobody apparently has a clue ...
I decided what the hell and 301 pointed about 50 good portuguese domains (relevant to site content and categories) to my site. Not all to the main page but mostly at different categories.. Say, peças - to autos category, justiça-to legal/attorneys...
Let's see how it goes. So far it helps with new listings and apparently does not hurt ranking (already after 3 weeks at 1 page of G for a couple of search strings I target).
I am not in a hurry, anyway...