1. Meat in a Can a.k.a. Spam- Glass Ceiling
2. Dispenser for Adhesive Strips a.k.a. Tape dispenser - Mild Mild West
3. World Wide Web a.k.a. Internet - Murdoch.com
4. Using half silvered mirrors (two way mirrors) in interrogation rooms - In the Altogether
5. Potato Cooking Room a.k.a. Microwave - The Tesla Effect
6. Murder Mystery Board Game a.k.a. Clue - Downstairs, Upstairs
7. Paint by Numerical Value a.k.a. Paint by Numbers - Monsieur Murdoch
8. Tiny portable telephone a.k.a. Cellphone - War on Terror
9. Sound activated light switch a.k.a. whatever the hell this is currently called - Invention Convention
10. Viewing Area of a Large Tower a.k.a. C.N. Tower - Cloud of Doom
11. Frisbrim a.k.a. Frisbee - Loch Ness Murdoch
12. Scrambler a.k.a. Scrabble - Republic of Murdoch
Oh and I think he also 'invented' hangman in an episode, not sure which.
Don't think it's Hangman though.Any others?