Re: tipping in the USA a little stressed about it
"The Simpsons" said:
Burns: Bravissimo, Luigi! Bring us your finest bottle of vino!
Luigi: Hey, you trust-ah Luigi, huh? He knows-ah what for to make-ah really nice the amore.
Jackie: Oh, Monty, I've never been to a more romantic restaurant.
Luigi: [heard off-screen; entering kitchen] Hey, Salvatore! Break out the cheap hooch for Mr. No-Tip and the dried-up-ah zombie he's-ah captured!
Yes the world would be a lot easier without tipping. But it's in America, so get used to it whilst there.
Definitely don't be all uppity and insist on never tipping. This is never good, no matter what your beliefs on the subject are. Sure, in principle you may be right, but don't expect to be sociable, as a minimum.
That said, arm yourself with some loose change - i.e. plenty of $1 and $5 notes. Usually when you change currency you might well end up with some of these, especially if you end up "cleaning out" the bank's daily stash of US dollars during your conversion

Another alternative is to break large bills by going to a store or something when you arrive in the US and buying a small item like a chocolate bar, then insist on some loose change (explain it to them, they should be alright with it).
I think tipping is not so annoying once you get used to it. Sales tax (and other taxes) are more annoying - unlike Australia, marked prices do not have to be all-inclusive of taxes in many jurisdictions. For example, a hotel room in New York may be subject to any of about 3 kinds of tax which is added to the advertised room rate that you see on the website.
Now for how much should one tip. In general, expect to pay anywhere between 15% (optimistic!) to 25% of your expenditure for tips where applicable. This is not the hard rule, it's just a budgeting guideline. It probably pays for you to be a little bit on your toes with math (can you quickly calculate/estimate 15% or 20% of an amount?)
To get you started, check out the USA article in Wikitravel and skip to the section labelled "Tipping":
United States of America - Wikitravel
This thread on Flyertalk has a nice rundown on tipping; you can also add your question to it (I'm sure there'll be no problem having the thread bumped, even though it's showing its age):
Tipping in America? - FlyerTalk Forums
Yes there are hundreds of posts there (it probably helps to join as a member of Flyertalk (free) and then go to the Control Panel and change the number of posts to the maximum, so you don't have to keep changing pages frequently), however there is a wealth of information there.
I've posted some questions of my own about tipping in this post:
FlyerTalk Forums - View Single Post - Tipping in America?
And the replies to my questions are here:
FlyerTalk Forums - View Single Post - Tipping in America?
and
FlyerTalk Forums - View Single Post - Tipping in America?
Some general comments:
- If you don't like the service, call the manager. If it doesn't get resolved to your satisfaction, you don't have to tip; at least you have a verified reason. But not tipping (or tipping a penny) should be a last resort. Bad service may simply warrant a lower tip (e.g. 10%). In any case, "undertipping" may result in someone chasing after you - be prepared to give a good reason (it doesn't mean you're in the wrong, but you can't just willy-nilly undertip or not tip at all).
- Be careful in restaurants: if the food is bad but there is nothing wrong with the wait service (or it is excellent), a lower tip is not necessarily the appropriate action! In this case, provided the tips aren't pooled and shared with the kitchen, you are penalising the waiter who offered you good service; the fact that the food was not good is not his/her fault. Again, call the manager (may be able to negotiate discounting your bill or offering free courses / replacements).
- Where there is horrid service - with or without a manager - no tip may be applicable (e.g. taxis).
- New Yorkers seem to expect a solid 20% as a "baseline" tip. Everywhere else which isn't too swanky can probably work with 15-17% as a "baseline".
- Feel free to tip more if the service is excellent.
- If you forget to tip, there's no shame in going back and fixing your mistake (with a profuse apology to go with).
- Try not to let on that you don't know how to tip. Don't ask the person who needs a tip how much you should tip (chances are you won't get an honest answer, or something indifferent like, "however much you think, Sir/Madam"). Also, don't be intimidated by someone who suggests something along the lines of, "Since you are from Australia, you aren't used to tipping. Just letting you know a tip of 20% is customary." Personally, I'd find that kind of insinuation rude and probably tell the manager so, with a resulting smaller tip.
To give you some comfort about hotel porters, well, if they do nothing to help you, they don't deserve a tip, full stop. Merely opening the door of your taxi I don't think qualifies them to get a tip, but carrying bags does. On the other hand, carrying your own bags (and dismissing the porter) can save you the tip, and should not be construed as actively depriving the porter of a tip.
I hope that gets you started.