Next question - is there a type of GPS that can show relevant NOTAMS like temporary control zones or obstructions or is there a website pilots can go to where all relevant NOTAMS are shown on a map covering the area they are interested in?
As mentioned a few posts up, SkyDemon and AWARE both have ipad apps and self contained units that graphically represent notams and provide warnings, amongst many other bells and whistles.
And another question - if there was a low flying helicopter coming into the London heliport in bad weather would the control tower at the heliport be required to mention the NOTAM or are they not required to say anything to pilots?
They might choose to as a reminder but are not required to. It is the pilots responsibility to check and observe notams.