Stay away from Doorway pages- it's not an SEO rather the opposite.
Doorway pages are web pages that are created for spamdexing, this is, for spamming the index of a search engine by inserting results for particular phrases with the purpose of sending visitors to a different page. They are also known as bridge pages, portal pages, jump pages, gateway pages, entry pages and by other names. Doorway pages that redirect visitors without their knowledge use some form of cloaking.
Find more on Wikipedia: http://en.wikipedia.org/wiki/Doorway_page