Is there any seo advantage in creating sitemaps for small (3-6 page) sites? Will the presence - or absence - of sitesmaps have any impact on the serps?
Site map is Good way to approach search engine to read out all the content you have on your web page, it; doesn’t matter whether it’s 3-6 pages site it’s up to you, but if you do not comfort to do site map you can also do social bookmarking for each page by which you also will get index very quickly
Sitemap has no negative point. Also you can submit it to Google Webmaster Tools, Yahoo Webmaster tools etc for repeated crawl of all your pages.
Site map is very important to a website Site whether site have 3-6 pages or more, it doesn't matter. Its really help to search engines to read all pages very easily there.