You also asked about which 30x redirect to use. I'm also looking for this answer. We currently an ASP header redirect. I don't think this is best, but I'm not sure a 301 redirect can be used. I'd like to hear from others too.

This is what we have now:

lang = Request.ServerVariables("HTTP_ACCEPT_LANGUAGE")
real_lang = Left(lang,2)
'Response.Write real_lang
Select case real_lang
    case "en" 
        Response.Redirect "/en"
    case "fr"
        Response.Redirect "/fr"
    case "de"
        Response.Redirect "/ge"
    case else
        Response.Redirect "/en"

End Select

They automatically redirect people in the uk who type in www.google.com to www.google.co.uk

But, this is different from changing language on a visitor. I'm not sure what google would do if I was in Italy and used my american laptop to visit google.com. I don't think they'd switch me to www.google.it, but maybe someone else has this answer.

Using the browser language settings has worked well for us.

Hi Daminao,

I do a redirect based on browser language.  I'd stay away from IP/location based redirects. You can have English vistors in Italian locations that would be lost on your pages.

hth,

Vince