Hi Spud Skier,
In U.S. it works in a quite different way:
1st step PPL
(between 35-40 hrs total time but most of the people get it with an average of 45, the big difference is that pilots are required to demonstrate proficiency in what they call ground reference manouvers, quite challenging)
2nd step IR
(after 25 or 50 hrs of solo navigation, depends on which type of course you are taking, you can start the training which will include 15 hrs of instruction and a total of 40 hrs of instument time)
3d step CPL
(before being able to do flying exam you will need to have 250 hrs total even if by doing a different course, part 141, you can get the commercial with less than 250 hrs)
This step usually will include also a multi engine license, if appropriate training will be received, but in case you would be able to get a CPL without a MER.
At this point you can try to look for a job as FO or as PIC for operations like Bush flying (an hell of experience mostly if you do it in Alaska!!) or Crop dusting, Banner towing, Parachuting, every thing that will not involve the transport of more than 19 pax and with aircraft were the type rating it's not required.
You can also try do get your CFI and start instructing, then upgrade to CFII and if you have a MER you can also obtain a MEI (of course after completing the relative course)
To be able to get the ATPL you will have to have reached a minimun of 1500 hrs total (and many other requirements quite similar to the JAA exept the 500 hrs multi crew) and after passing a flying test.
You will be able to do the writen before that but it will expire after 2 years!!
Remember U.S. system it's really flexible, there are many option but the way I explained, in my opinion it's the most efficient.
For each step will have to take at least a writen test (for CFI there 2 or 3 I am not sure) a oral exam and a flying exam (exept MEI where the writen it's not required!!)
I hope this helped and if you need any other info about the FAA sistem I advise you to look at
http://www.access.gpo.gov/nara/cfr/c...4cfr61_00.html
here you will find something that is equivalent to the JAA FCL home page.
Good luck and Good Flying