You seem to somewhat simplify the entire situation.
Yes you can take a Singapore taxi to the Woodlands checkpoint on the Singapore side of the causeway. Maybe there will be a 170 bus at 3a.m. Google for the Singapore Bus schedule. Frankly, I doubt that one will be running at that hour. The MRT is definitely not running. You will pay 1 1/2X the meter to drive all the way across Singapore. An additional charge will be made for pickup at Changi Airport. There is no public transportation available when you arrive. The Singapore taxi will not take you into Malaysia.
Once you get to the Woodlands checkpoint, you walk upstairs thru Singapore immigration and back downstairs. It is possible to walk across the causeway, but it is a hike. Once you get across the causeway to the Malaysian side, you go upstairs and fill out the form for immigration and get your passport stamped. (The foreigner line is on the extreme right-signs in English) You then march through customs and downstairs where you are now in Johor Bahru.
The Larkin Terminal is not here, it is a number of kilometers away. You should be able to find a taxi to take you there. It will be at least 5 ringat. I do not know if there is a currency exchange open at the time of the morning you finally stumble out of immigration. You pay the JB cab in ringat, not Sing$. It seems from my observation, not experience, that you will have a tough time getting ringat in Singapore as there appears to be no official exchange for the ringat to Sing$.
This problem can be overcome because some of your fellow FTers have left over Malaysian currency. E-mail for info.
Once you get to Larkin terminal, there are buses to all over Malaysia. You definitely can get to KUL where you definitely can get a bus to Penang. (It may be Butterworth)
I suspect that you are on a tight budget, so I will offer what I think is a cheaper alternative overall or, at least, near equal cost.
Take a Singapore taxi from Changi to the Rocher Road terminal of the Singapore-Johor Express. Cost about S$25. Buy a ticket to Johor, if the bus runs that late for S$2.40 which gets you to Larkin Terminal. Buy your onward ticket to Penang (probably KL).
Or the cheapest way. Sleep at Changi Airport. Get the first MRT and get off at Bugis (You will have to xfr to a mainline MRT a couple of stops from Changi) (Changi is the end of the line and effective last week there are only shuttle trains). At Bugis, look for the exit for Rocher Road (alternative exit is Rocher CC) The bus station is about 2 blocks north and 1 block east (left). Get a Singapore map on-line and find Arab Street and also Rocher Road. The station is on the extension of Arab Street. The express bus takes you to Larkin Terminal.
I suggest you do a google search for "Singapore-Penang Express Bus" as well as one for "Singapore-Kuala Lumpor Bus". They may run from the same terminal, I know the bus to Malacca does.
The other alternative is to book a RT Singapore-Penang on Malaysian Airlines. They have a U.S. office, but no on-line ticketing or (I believe) pricing. You call their LA office and they call rates for you.
You will get 2000 NW non-qualifying miles for a SIN-PEN RT via KUL.
Edited to add.
I did some simple searching for you. You can build on it.
http://www.google.com/search?hl=en&i...ng+express+bus
The above is the first page of a google search. The first Malaysian Airlines flight out of SIN is 0950 via KUL with arrival in afternoon.
www.malaysianairlines.com
Please remember that if speed is your major consideration, it is over 5 hours by bus from Johor to Kuala Lumpur. I do not know how long it is to Butterworth and then Penang. Flying will be quickest. If you wish to save some money, you could fly Malaysian Airlines out of Johor Bahru, but it is not a simple matter to transfer between SIN and JHB. The airport bus leaves from the Copthorne Orchid (again google search because I am not sure it is the Orchid and there are more than one Copthorne in Singapore). The cost is S$18.50, although when I got on the wrong bus at JHB in January, it appeared that you could get on the bus at Woodlands Checkpoint, the fare the same. I do not know how to get to the pickup point, but it is researchable using google. The buses are timed to meet the arriving flights and I remember seeing a schedule on the internet. The cost from JHB-KUL-PEN RT should be less than $150.00U.S. if I read the Malaysian website correctly. It is 35 minutes (approx.) JHB-KUL versus at least 5 by bus.
Expedia has pricing SIN-PEN or alternatively one can do walk up fares SIN-KUL and book the KUL-PEN section separately with MH directly.
If you are originating out of JFK on NW, you will have a long 2 days of travel before arrival. If it were me, I would consider carefully my alternatives. BTW I just returned from SIN to the U.S. West Coast via NRT&HNL. It is a long tiring trip, especially in coach.
[This message has been edited by opushomes (edited 07-27-2003).]
Edited to add:
Location of money changer at Larkin Terminal
Go thru the entrance to the station from the bus platforms. The money changer is located to the right on the left side of the central corridor. Do not expect a great conversion rate to U.S. dollars.
[This message has been edited by opushomes (edited 07-27-2003).]