lamp's read as lamps or lampz?

/s/ not /z/. Note that the devoicing of /p/ needs to carry over.

Thank you.

You know the "lamp's" is totally different to "(a lot) lamps", but they share the same pronunciation?

Yes. Disambiguation often comes from semantic context, not syntax or phonetics.
For example, some Americans tend to pronounce the words "rider" and "writer" the same with a /d/ sound in the middle. ( Some phoneticians have done experiments to see whether the length of devoicing is altered in potentially ambiguous contexts, but with no clear result).

Yes, there are many words that are pronounced the same way, and may even be spelled the same way, but have different meanings depending on context.
Homophones
http://en.wikipedia.org/wiki/Homophone
Homonyms
http://en.wikipedia.org/wiki/Homonym

I love reading what Fresco writes, even though I don't understand it.

I think this means "Americans talk kinda funny".

Voicing =vibration of larynx (vocal cords).
Consonants often occur in pairs theoretically distinguished only by whether they are "voiced" or not.e.g. /b/ (voiced) versus /p/ (unvoiced). Other such pairs are /t-d/, /k=g/ , /f-v/ etc. You can test whether voicing is a "distinctive feature" by whispering (devoicing) each to a listener and seeing whether he can determine what was intended.Some phoneticians argue that in the absence of the availability of voicing, during whispering , the duration of devoicing is manipulated by the speaker as an alternative clue...but this would not be required if the semantic context (whole sentences versus single words) made the whisper's intention clear. These issues exacerbate the complexity of phonetic theory with respect to the role of redundancy in signal transmission..

Here endeth the lesson.

Thank you. But any fule kno that.