There are various ways to deliver doorway pages. The first way is to create and submit a page that is targeted toward a particular phrase. Some people take this a step further and create a page for each phrase and for each search engine. Click through pages take you to a page which links through to the end site. You click through, but that page probably lacks detail about the hotels in question.
Some search engines no longer accept pages using fast meta refresh, to curb abuses of doorway pages.
In fact, sometimes resubmitting the exact page from another location does not gain the same position as the original page. Gateway Pages can be more sophisticated portals than a click through page. By submitting an invisible frame the user will click straight through to the site which it is pointed towards. The search engine will index a page which will never be viewed - and the user will only see the page which they are redirected towards. This doesn't act as a meta refresh, so the engines do not detect it as a redirect and there is no need to click on a further page in order to access the site which you want.