Referrer-based content - Does Google penalize?

[progex]

I plan on using .htaccess to redirect my visitors based on the site they come from when they go to my site.

Will Google penalize me from such redirecting?

[WebGuerrilla]

Google would only see the redirects if they passed a referral string that matched one of the sites you listed in your .htaccess file. Since Google doesn't pass referrals, they would simply get whatever content you have setup as the default for all "no referer" visitors.