
I've worked with Motorola and Nokia in Foxconn, I've found them very good, sure they use more manual labour than is probably best, but their quality can be very good. Their facility in Shenzhen is incredible, last time I checked, there was almost quarter of a million workers on the one factory site.
Other manufacturers that are there:
Apple
Dell
HP
Sony
Nintendo
Sony Ericsson
Microsoft
Talk of slave labour is overblown. The "cheap labour" is not all that cheap locally, they pay ok, you get cheap university on the campus and very cheap accomodation. It's considered one of the best places to go to first when arriving in Shenzhen from the provinces as they train you up and then you move on to somewhere else.
Not to mention that western companies do reguarly audit them, i know Nokia has gone on random checks for ID and proof of age to check for workers under 16.
Which, considering I started (part time) work myself at 14 years old, is not too shabby