I'm refining my technique but what Vekke says seems about right. I glide to the top, or just before allowing the momentum to carry me the last part, and then coast the downhill parts with the engine on (at the moment).
If the hill is quite long then I will pulse a little on the preceding flat and then ease back but stay in gear for the climb just enough to reach the next peak, reducing my losses as much as possible. If the hill is quite long I will aggressively P&G up it too - i.e. quite a sharp pulse. I have one very steep section which I used to lose about 2-3 average MPG in climbing, that loss is down to around 1. Unfortunately this section includes people turning so more often than not I end up having to stop/start on the hill anyway.
If the downhill section is steep enough then I will glide in a high gear to take advantage of the four 9s (9999 MPG) which is more or less like gliding with the engine off. The high gear (I have a 6sp) reduces the engine drag so the glide is still quite long.
I have a section of traffic when it is all stop-start but quite a steep downhill section so I have started cruising slowly with the engine off for that section. On the SG2 it shows me as being at about 45 at the start of this section and still 45 at the end, normally idling will drop this to 35. The downside is that the engine and car are not warm by this point so I have started wearing warm walking socks to keep the feeling in my toes.
How do people find others reacting to P&G ? I have the technique down reasonably well where passengers are concerned so that they don't feel uncomfortable - the P part is less aggressive. Other drivers can be a pain, one guy I pulsed in front of thought I was starting an acceleration race and decided to try and tailgate until the G part.