Hey Dusty,
My takes on your questions...

>1. Is higher salary usually earned with the >certification, paying back the cost of the >certification itself and generally making life > easier in China?

I would disgree a bit with Henry on this one. I've seen a zillion job ads, and I've never noticed a significant correlation between salary and a cert requirement. Requiring a cert doesn't in any way seem to guarantee more money, better conditions, more honest treatment, or any other benefits. The one thing I'd say about a cert in China is that it does open a few more doors...some jobs do require a cert, and cert holders will have these jobs as options where others will not. In general, these are not good reasons to get a cert if you want to teach in China.

2. Is an online TEFL program worthwhile?

No. If you're going to go this route, just buy one of those certs they simply tear off of a roll, and save yourself some trouble.

3. Does such a certificate actually help prepare a person to teach English as a second language?

As Henry indicated, it very much depends upon the program. IMHO for a program to be of any value in building a teacher, it has to be real-time with live classes and teachers...which eliminates all the online and correspondence courses. The CELTA program has its fans and detractors, but it will have at least some value if you're a neophyte teacher. I also can recommend the Boland School...I know the faculty and many graduates, and it seems to be quite a good program. There are others as well.

A cert is of some value if you plan to teach in North America, the EU, and perhaps Japan. In China I feel they're of questionable worth unless you really feel you need some preparatory teacher training.