Around this time last year git added a "smart" HTTP transport that is faster than the old HTTP transport (and in some cases faster than SSH too). And a few months later GitHub added support for this new HTTP transport and made it the default selected url for repositories (that you aren't a contributor for).
There aren't any major advantages using https over ssh to access your GitHub repositories, it's just more simple to use your username/password instead of adding your ssh key. The only other advantages is that it's easier to set up HTTP proxy for git (
git config --global http.proxy proxy:8080 vs ssh config) and being able to use more than one GitHub account (which you shouldn't since anyone can add you as a contributor to a project).
One major disadvantage is that it asks you for your username/password each time you interact with your remote repository (clone, pull, push, etc). To solve this, I decided to write a program that stores your username and/or password in your keychain so git will ask once for you username/password and retrieve it later so you don't have to type it again. If you only want the program, skip to it.