The going overland between the US and South America to save on the flight is an adventurous idea, but a very dangerous one. From what is on travel documentaries for that area of the world, you might as well wear a sign saying kidnap and rob me I am a rich tourist. Muggings, kidnappings and busjackings are daily practice in some of those central american countries. I watched a documentary on El Salvador which showed the way gangs basically run the roads there where bus drivers either pay a rent to gang leaders or have the gangs jack the bus along with all the passengers luggage. Doesn't sound like the sort of thing I would like to risk happening to me if I could get out of it! You would probably end up spending more getting there than you'd save on the airfare and have a good chance of having something bad happen to ruin your trip.
They used to have a ferry operate from Europe - Egypt, but they stopped doing it so now your only option without having a mega fortune for a major cruise liner is a flight, but your itinerary is going to be extremely hard to work the exact way you want it to without spending huge amounts of time in airports and on flights as you are in effect doing a two and a half times round the world trip on the one ticket with all the ups and downs you are doing in the itinerary. Organising any itinerary within South America (without including extra separate flights) is pretty difficult.
On your RTW ticket, wherever at all possible you would want to stick with the original dates you decided upon unless you are talking about staying extra months (this is especially important in South America where some routes don't operate daily and none that are valid on a rtw ticket operate more than a couple of times a day). With airfares say for example they have 200 seats on the plane in economy class, just because you look on the internet and see that a flight has availability in economy class does not necessarily mean that it has it in the class you require. On the One world continent based fare you can only book in L Class and in that 200 seats I was using as an example only 9 seats might be L Class (in some cases none might even be released) and that is when the flight was first listed. So if you left it to the last minute and changed your mind, it could be weeks or even months in peak travel time before you could get on a flight with L Class seats left or you may strike it lucky and get one the day before (but the latter would be rare especially to, from and within South America).
Have you look in to the visa situation with countries you are talking about visiting? I think that as a tourist in Egypt you can stay for 30 days on a standard tourist visa without going and getting it extended (You wouldn't want to stay for more unless you knew someone there). So you would most likely need to go to Jordan or another close by country in the Middle East to avoid visa problems. In a visa guide for Australian passport holders it says that visas for indonesia can be arranged on arrival for stays up to a maximum of 30 days. A lot of the time the rules are the same for US passport holders as Australian passport holders, so I would imagine this is the same and would mean if you plan on being there 2 months you would need to apply before you went.
You will not get a flight on the One World RTW ticket that goes from Egypt to Indonesia. You would need to go back up to Europe or across to Amman/Jordan. From there you could head further across to Bangkok - Singapore - Denpasar or Jakarta. That part of your itinerary would probably need to be Madrid - Cairo - Amman (could possibly have that as an overland section) - Bangkok - Singapore - Jakarta - Sydney. You really should reconsider the Indonesia bit because having that as part of your RTW ticket is basically making the rest of your ticket almost impossible to make a valid ticket with and certainly not doing what you want. Even if you landed in Singapore and got a cheap flight from there you are still limiting your options to only a couple which is going against your open as possible policy.
[ Edit: Edited on Oct 25, 2008, at 6:03 PM by aharrold45 ]
i just read your last post and i so appreciate the info!!! Just so you know, I am really open in terms of most of my stop overs via plane, I would appreciate stop overs because i figure it means more places to see. In South America I would be fine with stopping over in most places, granted if I can stop over for 4 days or longer to enjoy it would be nice, rather than taking buses all over. Also in the Meditterean area I really wanted to see about visiting Portugal, S.Spain and Malta (all or a couple whatever is doable) and flying to Egypt from there is cool also. It just seemed like it would be close by to take a boat. I will likely stay in Egypt under 30 days but will be in the Meditterean/N.Africa region for 2 months. I am basically open but focusing on the regions I would like to be in rather than exact areas (in some cases anyway) like I would really love Indonesia but I can likely get there overland from an easier point that works better to get a cheaper tix. My main areas that I really want to see are: Egypt, Brazil, NZ, Malaysia area, Fiji, French Polynesia, and whatever other islands I can get to in Oceania and the Carribbean....(Namibia, Ghana and Senegal would be nice but a bit out of the way I guess so I have kept them off the list....but since you seem like an expert they are no longer a secret...but I will not be heart broken without them either...so if they end up being a stop over that is cool...though they are out of the way) Anyway visiting my main areas in the order that best compliments sunny weather....as much as possible anyway' is my main objective....and seeing islands are also an objective....and I was hoping for a month or 2 in each region to get more familiar with the area. Stopping over in a relatively safe-ish region that is scenic and kinda sunny is great too......What are your suggestions?