There are two solutions for comprehensive sync between your Palm Pre and desktop or laptop computer. Missing Sync will only work with Macs for now (Windows soon to arrive), and PocketMirror only works with Windows machines (no news on a Mac solution). So, Mac = Missing Sync, Windows = PocketMirror. With that out of the way, both apps have very similar functionality : they allow you to sync your Calendars, and Contacts between your Palm Pre and your computer. 

Both will do this over WiFi, so no need for cables. Missing Sync has a neat proximity feature that syncs automatically when you are in range. PocketMirror is basically a simple Outlook sync. You don’t need an MS Exchange server, but you need to have MS Outlook installed on your Windows machine. Missing Sync does more: you can sync music and video files (the desktop app will correctly format files for you), ringtones, bookmarks, and regular files in addition to Calender, and Contacts. Both are free now on the Palm Pre apps catalog, but I don’t expect them to remain free for long.