I'm using SugarSync to sync files between my phone and my computer, but I'm not sure if things are actually working as they should.
It would be great to watch Android network traffic in real time.
Does anyone know of an app?
Isn't really an answer, but...
There is WiFi Analyzer which shows more information on the wireless networks your device can reach. It gives you more detail than the average user would require.
As far as I know, there is no application available on Android (yet?) that can "sniff packets".
Would be an interesting application to have in the pocket.
There is an app called 3G WatchDog.
It can monitor 3G data transfer and Wi-Fi traffic. A pretty neat application.
Click image for larger version
You can view, sniff, and save actual network packets, however this requires root access.
Shark for Root app does this.
You don't need root to do this! Android apps can utilize the VpnService API to capture packets without root.
Here are some apps I found that do not require root:
Network Log is an app quite simple to use. It shows real time packets in a human-readable way as well as statistics. It takes it directly from iptables, hence you need a rooted device.