Sitemaps - Worth creating?

[Phaser]

Is it worth creating a sitemap with Google?

Am I likely to notice much difference in terms of search results etc?

Cheers.

 

[Phaser]

I didn't mean an on-site one. I meant one you upload to Google..

https://www.google.com/accounts/Ser.../webmasters/sitemaps/siteoverview?hl=en&hl=en