Yes, www.yourdomain/yourblog/ is still very important, it's better for your SEO than www.yourblog.yourwebsite.com , but www.yourblog.yourwebsite.com is better t

Yes, www.yourdomain/yourblog/ is still very important, it's better for your SEO than www.yourblog.yourwebsite.com , but www.yourblog.yourwebsite.com is better than having no blog at all. Well, as for Tumblr, posterous...and similars, you can try a reverse proxy hack but I'd suggest to just set a folder on your server and drop wordpress on it.