I like the gridcoin logo itself, sans text. Looking at it, it looks like something that you would see in a game like Deus Ex or a similar setting and it would go great as a simple addition to an article of clothing. It has a futuristic cyberpunk-esque look to it and I dig it.

I'm a minimalist myself, so it would go on the outside shoulder (facing out like a shield) or positioned like a badge on the top-left front of a shirt or hoodie just a bit above the pec muscle. I also wouldn't mind having it on the back in the top-center two or three inches below the collar line.

Some people may enjoy a larger version of the logo on the back of a hoodie or fitwear like a moisture wicking shirt, though personally I'd stick with the smaller logo.