If you have ever been to a blogspot blog, you would have definitely noticed the 40-pixels wide Navbar that appears by default at the top of every Blogger-powered blog.
This navbar is like Google's own version of StumbleUpon where visitors can search existing blog or discover new Blogger blogs just by clicking the NextBlog link. And if you are logged-in to your Google account, the navbar turns into a personal dashboard toolbar similar to what you have seen on Wordpress.com blogs.
Though Google provides no "disable button", tons of blogspot users have hidden the navbar on their blog through simple CSS tricks which available for both new Blogger and classic Blogger templates.
The next important question is whether you are violating any Google policies or Blogger's Terms of Service by removing the navbar ?
The Blogger's TOS page makes no reference to navbar while Google representatives in the Blogger support group (nickname: Blogger Employee) have always ignored discussion threads seeking an official stand on hiding navbar.
There's some hope now. Google recently organized a road show in select Indian cities to promote their Blogger platform. Ankit attended the event and requested clarity on the navbar policy from the Googlers present at the roadshow. They immediately called up their team based in Google's Bangalore office and confirmed to Ankit that it's legal to hide the navbar.