teaching english for i.t

If you're teaching IT guys, they already find IT interesting! You should immerse yourself in their specialties, try to get a basic understanding of the software (or whatever else) they develop, and use any appropriate journals or articles written in English as course material. You should also examine their e-mail outbox for any mail they've written in English, and have the class review and correct it.

IT guys (and engineers in general) love to explain things, so have them go to the whiteboard and diagram something technical, then explain it in English. Then proceed to error correction, etc.