Multiple TLDs for domain and page ranks - use of 301 redirects

Sorry if this is a stupid question, i have look in various places for the answer to my question but to no avail.

It is on the subject of domain protection, as in registering .com .net .org etc for your domain name .... this to many seems a good idea (and i believe godaddy offer this service).

My question is what to do with these domains?

Now i know that google spiders treat example.com and example.net etc as different urls and so pointing them both (or all TLDs) to the serve IP - essentially duplicating content - WILL badly effect pagerank.

Does 301 redirects prevent any bad effect on PR
or does a it still have an effect?

In other words is 301 redirects an effect way of protecting your name, and mistaken users typing or linking to the incorrect TLD (say in a forum or blog or whatever) - i dont think a .net/page.html will redirect to .com/page.html just .com - so shouldnt count as 'duplicate content' ... i assume using the 'url cloaking' in registrar DOES count as duplicate content.

or is all of the above bad PR ... and landing pages the only way to protect your domain ?

thanks in advance

Using a 301 redirect is the best method of pointing your other sites to your main web site. If you have any PR on those other sites then this PR juice will be passed on to your main site. This is what I do and seems to be the norm.

Agreed 301 rederict of all variations of your domain is what you need to do and is fine in Google's eyes.