I just noticed this option - "Submit feed as Sitemap" in Google's "Webmaster Tools". My site is a forum and has a separate feed for each sub-forum. Should I select "yes" or "no" for individual feeds? and why?
This is just for convenience if you cannot create a sitemap. I would create sitemaps (properly splitting it into seperate files so it is easily parsed by the search engines) and then you can use it for Yahoo... Bing.. etc.
a lot of platforms (wordpress especially) have plugins to automatically generate and send sitemap updates to google whenever you make changes to your site