Updating Sitemaps every day, black hat SEO?

[iWebTrack]

Hello everyone -
I heard this thing on one of the SEO conferences I attended, during a panel, one of the speakers said that updating the sitemaps every day, and changing the <lastmod> node to the current date, it will move up your website in the rankings.
I can see that is true and we are going up just with updating the <lastmod> node, but I want to know if we can be banned from Google because of that.

Thx.

[goodroi]

Google likes fresh and regularly updated pages. Google does not like people that take shortcuts and try to manipulate their algo to promote poor content pages.

Ask yourself if a Google engineer comes across your page will they be happy or angry?