Optimization, google and blogging

how can blogger.com affect my widget rental site optimization

[Robert123]

can blogs really boost a sites placement with many links pointing to a particular site, or moreover, are there instances where this would hurt a site?

[Robert123]

Anyone?

[mrwhy2k]

Of course they can help, they are links aren't they.
Why is it that the George W. shows up #1 for "miserable failure" in Google... blog links.

They might hurt you if you get Google Bombed, and it might hurt if you link back, but otherwise, you can never be penalized by external links.