Question: I would only like a password prompt at login and lock screen (i.e, to make sure others don't use my computer). However, when I am at my computer, I do not want to be prompted at all for my password, for any reason.

I realize it is a "security risk", but I am a developer and the loss of convenience is more important to me. 

Adding "NOPASSWD" to sudoers will stop it from prompting at the shell, but stuff like Update Manager and Ubuntu Software Center will still bother me.

Any help is appreciated. Thanks!

Answer: 
OK, I found the answer to my own question. Turns out this ridiculous non-sudoers-respecting password prompt application is called PolicyKit. No way in hell would most people know about this application, so it is hard to Google for. This question will put an end to that!

Fix is simple: in /var/lib/polkit-1/localauthority/50.local.d, create a file called disable.pkla (or whatever you want, as long as it ends with .pkla) with the following contents:

```
[This name does not matter]
Identity=unix-group:admin
Action=*
ResultActive=yes

```

Log out and back in, and enjoy!
If you make your own launchers for them in the style `sudo update-manager` then they will start with full privelidges but not prompt you. The default shortcuts to these programs are structured to prompt you before they run, so just don't use those.