I understand that the Palm profiles we create when we set up the Pre backs up certain device info; however, I have read at PreCentral that not everything is backed up. Since I am planning to return one of the two Pres I currently have in the next couple days, I was concerned about losing photos (primarily) that I had taken with my first Pre. This issue and my general curiosity prompted me to play with back-up and syncing options. Here's an article about this subject for further reading.
Syncing with iTunes
This process works pretty seamlessly. Aside from the fact that protected media (TV, video, games, and some music) won't sync, the Pre syncs with other content as an ipod would. That's been pretty well documented.
Using Pre as a USB Drive
This option, offered when you plug the Pre into your computer, is pretty nice for manually adding files to the Pre. I wanted to pick and choose certain pics from different files on my Macbook Pro, for example, and with my Pre connected as a USB drive, I could basically go through files and images and drag and drop the ones I wanted onto the Pre icon that appears on your desktop when you choose this option.
Syncing with "Missing Sync"
Prior to trying a corded sync last night, I had only attempted the automatic "proximity sync" with "Missing Sync" (Beta for Pre) and not had any luck--seems my Pre and Mac just wouldn't play together wirelessly. Last night, when I connected my Pre to my Macbook Pro, "Missing Sync" automatically launched and did its thing. I played with the settings and took a few screen captures so you could see how it works.
All in all, I would say that each of the above options are useful in their own way and can be used in combination to accomplish different kinds of syncs. The iTunes sync is great for keeping the Pre current with my downloaded music and podcasts (though the Pandora app is so great, I find myself listening to my purchased music less). The USB "drag and drop" option is great if you just want to add a few things manually (not automatically, every time). And the "Missing Sync" works well to automatically back up photos you take on your Pre (as opposed to automatically just adding photos from your computer to your Pre through iTunes).
One thing I have not figured out (but am hoping is covered by the Palm profile I created) is how to back up "contacts" from my phone to my computer. I must be missing something because I know that you can sync contacts with both iTunes and Missing Sync (if you want to override info on your Pre with info stored on your computer), but I can't seem to find how to send all the contacts from my phone to my Macbook. I tend not to add contacts on my computer--only on the Pre. If anyone knows and can tell me in a comment on this post, I would appreciate that info.