Came across a book review for a recently published dictionary that links up the different terms in China, Taiwan, Hong Kong, Singapore. Was going to send this via email to friends learning chinese but reckoned it could also be useful for the rest of the community.
(http://www.amazon.com/New-Century-Global-Chinese-Dictionary/dp/B003OFUUHQ)
Thought would share this with the advanced learners who may be interested in the nuances. Its quite amusing to find the right term by trial and error, like asking for taxi & how to use the aircon at hotels in the region. :-)