I'm your huckleberry.
I tried doing this exact thing. At work I have Outlook with an Exchange server and my work calendar. At home I have a Mac with iCal. I wanted to sync both calendars with the iPhone. I could do it, kind of. There were issues, some of which seemed like bugs and they may have been fixed but I doubt it.
I would sync with work computer and appointments on the iPhone would go to Outlook and appointments in Outlook would go onto the iPhone. Then I would go to sync with iCal at home. iCal wanted you to specify a calendar to put appointments in that were created on the iPhone. If I remember right you could pick any calendar and it would put the appointments in the last calendar created. Then when I went back to work to sync with the work calendar it would not know that the appointments that it transferred to the iPhone were the ones it already had so it would move those to Outlook, giving me plenty of duplicate appointments.
I feel a fix to this would be to allow multiple calendars on the iPhone like iCal has. That way you can tell iTunes at work to sync your outlook calendar with the "work" calendar on the iPhone. You can also tell the iTunes at home to sync your home calendar(s) with a specific calendar on the iPhone (or provide a mapping to multiple calendars) and then you have everything nicely binned with the ability to view only specific calendars if the view is too cluttered. I would love to be able to keep a copy of my wife's and kids' calendars on my iPhone without having to look at them all the time, just when I want to see what is going on. I would also like separate views of my home and work calendar. I definitely don't want all those home appointments on my work calendar for others to see. I have suggested this to Apple a long time ago through their feedback system. I am unaware of any action they are taking in this direction.
For me this is a bigger issue than MMS or copy/paste (although I would use copy/paste a lot).
In the end I put the few work appointments that are important to me on my iPhone manually. It isn't many and they are recurring so I don't have to do it often.
It seems as though I am not understanding the iphone functionally clearly AND that my question is not clear. Based on the numerous replies and many people having different answers, it currently seems to be impossible. So, Let me try again to restate:
First, I can not use mobile me due to my profession limiting MANY MANY internet sites from work.
Second, I will be syncing my music from my home machine so that is no issue, I know that can be done.
Third, I would like to sync my contacts and calendar from two different computers. The first machine, at work, is a windows machine running outlook. The second machine, at home, is a mac running entourage (I do not use ical or mail).
So, would it be possible to sync both of those computers calendar and contacts to one iphone? (My work calendar is the most important, but I want to be able to make changes on my computer at home and then sync again if need be.)
I do not want to use any different software, or a website to do this. I just want to know if the iphone can do it. I know that my old 8525 and the new Tilt will do this no problem mind you I need to purchase "The Missing Sync" for my mac, but it works. If the iphone can do it, I will purchase one, but otherwise, I will stick to the tilt.
Thanks for all the great responses, it explains why I was unable to find a definitive answer on the web.
Chris
You can do it if you have an exchange account and a .mac (MobileMe) account and they're configured to sync over the air. Unfortunately, you can't do it through USB to two different computers. As a caveat to this, that statement is based around the current version of iTunes and the new version that will be released with Version 2.0 of the firmware may change that
Phil, based on what I know about the iphone and your answer I believe to be true.
I was under the impression that you could use multiple computer to sync via the cable for each different function (calendar, music, contacts), but you could not sync from multiple computers for the same function, just as you can not currently sync from multiple computers for your music collection on an ipod, legally.
You can create a gmail account, and pull your calendars into a gmail account. I believe gmail calendar syncs with outlook, though you need to install google desktop I believe. Might be a solution to avoiding the tilt
Techincally this will then allow you to have a web version of your calendar that would be accessible when you are not at work or home, and do not have your phone.....
Try this link -
http://internetducttape.com/2006/08/11/the-holy-grail-of-synchronization-how-to-synchronize-microsoft-outlook-multiple-locations-google-calendar-gmail-ipod-and-mobile-phone-with-funambol-scheduleworld/
Sorry I do not know how to do a multi quote in a post . . .
I can not add any additional software to my work machine. They have us locked up pretty tight. I can however sync with my phone though . . . .
Wirelessly posted (Mozilla/5.0 (iPhone; U; CPU like Mac OS X; en) AppleWebKit/420.1 (KHTML, like Gecko) Version/3.0 Mobile/4A102 Safari/419.3)
I just plug my iPhone into each computer and sync. I just make sure iTunes is configured correctly to the address book and calendar.
I just did this last night. iTunes asked if I wanted to sync the iPhone with the different computer and poof, done.
I've had no problems. No duplicates, no spending money on extra programs.
Can you be more specific in how this worked for you? It is similiar to when you plug in an ipod into a computer that is different than it's home machine?
Thank you in advance!