Jellybean-surprise! (Or, how to change "localhost" to whatever you fancy)

UPDATE, 04/25/18: 

I recently realized I could set localhost aliases that mapped the different roles of the software I'm building. For example, if an application has three user roles ("client", "coach", "admin"), I set up aliases for each that point to a logged-in user of that role. So when I visit client:3000 , I know that I'll be logged in as a client. When I visit admin:3000 , I know that I'll be logged in as an admin user, and so on.

ORIGINAL:

There are lots of "very important reasons" you might want to edit your hosts file, but let's be serious - I did just for fun. The following instructions are for Mac; find instructions for Windows here and instructions for Linux here.

1. Open your hosts file

Open your hosts file from terminal with whatever text editor you prefer: $ sudo subl /etc/hosts, $ sudo vim /etc/hosts, $ sudo nano /etc/hosts, you get the picture. You might be asked for your admin password.

Sample hosts file:

2. Add your new aliases

Copy the line that says 127.0.0.1 localhost and add a new line, but change localhost to whatever you want:

Save (after potentially entering your admin password again), and you're set! You can have multiple aliases direct to 127.0.0.1 - they don’t override each other.

Now, instead of seeing localhost:3000, you can be greeted with

and who doesn’t want that?