Every once in a while I need to share some code snippets, and Gist has been the best way to do this so far. Using the browser wastes a few mouseclicks, especially if you already have the intended contents (either entirely or partially) in a text file, so here's a better way to do this:
sudo gem install gist
gist --login
gist myfile
A new gist containing the contents of myfile (along with the appropriate source formatting) will be created, and you should see something like
https://gist.github.com/3d82745c84c8f44dd51c
indicating success.
Note: If you want to upload anonymously, try gist -a myfile instead of the above.