Is it worth submitting your website sitemap to Yahoo?
I have noticed that by submitting the sitemap to Yahoo search engine didn't index my pages quickly, but in Google it indexes my pages faster than Yahoo. Have you noticed this too in case of your website?
I noticed that if I submitted my site map to Google, it got indexed by Yahoo on its own pretty soon after on it's own. I didn't need to submit it because their spiders picked it up from Google anyway.
Yes, Its worth to create and submit your sitemap to Google. Its not that it improves the site indexing speed, although it can help but backlinks speed this more. But the most important is that if the sitemap is missing from your site Google takes that negatively.
In almost all cases I like Google as a search engine over Yahoo. Its the speed, the content, and it's accuracy. I've submitted mine to Google but not Sitemap at this time. I think everything you do to market your site is worth the time. No matter how small.