[clivehawkins]

It's not an ESL book as such, but if you'd like some fresh ideas there's a really good section in the back of the teacher's book to Natural English (Intermediate), published by Oxford.

There are 6 Teacher Development chapters:
How to - activate vocabulary
- introduce new language
- teach listening
- monitor and give feedback
- do free speaking
- teach phonetic script

It's great for helping you 'get out of a rut' as far as your teaching is concerned. I admit mine was getting pretty stale and this gave me one or two new ideas for a fresher approach.

Hope that helps.