I work in IT and I more often than not block on the word "computer" - I can relate. I usually feel the block coming and replace "computer" with "machine" but still... not the word I'd prefer to use. I notice that if I'm using a headset and do something else while speaking, I stutter way less than if I'm just sitting there idle. Try doodling on a piece of paper for example? I'm way more comfortable speaking on the phone while driving (Bluetooth handsfree), probably because I'm so focused on driving that I "forget" to stutter. I don't know. It's weird.