Generally the voltage is fine - most laptops are set up to take 110 or 220 on the fly (no need to tell the computer what it's being fed). For the plugs, you may want to look at this page

http://kropla.com/electric2.htm

for the right plug(s). Some top end hotels catering to US travelers have US plugs at the desk in addition to the local plug (i.e., Conrad Hong Kong), but I wouldn't count on it.