I have several sites that have cross domain canonical tags setup on similar pages.  I am unsure if these pages that are canonicalized to a different domain should be included in the sitemap.  My first thought is no, because I should only include pages in the sitemap that I want indexed. On the other hand, if I include ALL pages on my site in the sitemap, once Google gets to a page that has a cross domain canonical tag, I'm assuming it will just note that and determine if the canonicalized page is the better version.  I have yet to see any errors in GWT about this.   I have seen errors where I included a 301 redirect in my sitemap file.  I suspect its ok, but to me, it seems that Google would rather not find these URL's in a sitemap, have to crawl them time and time again to determine if they are the best page, even though I'm indicating that this page has a similar page that I'd rather have indexed.

A question came up today on how to correctly serve the right status code on pages where no search results are found. I did a couple searches on some major eccomerce and news sites and they were ALL serving status code 200 for No Search Results Found http://www.zappos.com/dsfasdgasdgadsg http://www.amazon.com/s/ref=nb_sb_noss?url=search-alias%3Daps&field-keywords=sdafasdklgjasdklgjsjdjkl http://www.ebay.com/sch/i.html?_trksid=p5197.m570.l1313&_nkw=dfjakljgdkslagklasd&_sacat=0 http://www.cnn.com/search/?query=sdgadgdsagas&x=0&y=0&primaryType=mixed&sortBy=date&intl=false http://www.seomoz.org/pages/search_results?q=sdagasdgasdgasg I thought I read somewhere were it was recommended to serve a status code 404 on these types of pages.  Based on what I found above, all sites were serving a 200, so it appears this may not be the best practice. Any thoughts?