This was posted earlier...
" Syncing on 2 Computers
I have a Apple computer at home and a PC at work. I can sync my iPhone with both, well merge is more like it.
Under the info tab, you have the option to control what to sync. For my Mac, I choose contacts, calander, and my safari bookmarks. You have similar tabs to control photos, music, and videos. Based on your message, I think you already know this but wanted to right it down for completeness.
When you sync the first time, the computer and iPhone will be syncronized.
Now, when you go to your second computer. In my case, a PC running Windows XP SP2. I'm using Outlook to manage by calendars and contacts on this PC. You go to the info tab and only select the calendar and contacts for syncing. When you sync, the system ask whether to merge or overwrite the information on my iPhone. You need to MERGE the information. You continue to use the Merge option when syncing between the computers.
This approach works for me. There may be some issues with the initial merge, like duplicate entries the first time the machines are synced. You can either delete the duplicates or delete all the entries on one of the devices. In my case, I choose to have the Mac as the master. All my Outlook (i.e. work appointments) were already in the iCalendar. Therefore, I deleted all my contact and calendar entries on Outlook to initialize the process.
Using this approach, I'm able to sync on 2 machines. My music, photos, and videos are completely controlled on my Mac while my calendar and contacts are essentially merged together."
Hope this helps --- Thanks to "louielui" for posting this---
