An old project I stopped working on. Name is kinda explicit, this SWEP will turn you into a talking Portal turret as soon as you select it. You will start undeployed, right click to deploy, right click again to retract. Left click to shoot, obviously.
You can also use E and R, or whatever keys are bound respectively to Use and Reload to open the voice menus.
Of course, players and NPCs will be able to throw you around and tip you over, so be careful.

Lots of unresolved issues, such as insane lag and unability to aim correctly on laggy servers (isn't that normal?), NPCs not attacking the player when transformed into a turret, lasers not rendering properly, and other annoying glitches I don't remember.