When using ATMs/Cash Machines/Bankomaten/Geldautomaten give them a good wiggle before inserting your card. During 32C3 a Skimmer device had been found at an ATM at Bahnhof Dammtor. This is just a reminder, you should do that every time you use your card.
Come as you are, as a friend.
Label ALL your gear in a consistent manner. (Twitter handle and DECT numbers have proven to be working well.)
In case something gets lost it can find its way back to you.
Power and Chargers
Laptop and Devices
Wireless and HF
Cables and Adapters (Dongles)
You'll forget at least one anyway, so don't worry. Bring a spare to help out friends!
Networking (wired and wireless)
Mobile and Communications
It is not recommended to connect your smartphone to the congress wifi -- [ ] if you still can't resist, here are a few things to consider:
If you are unsure if there are still some services transmitting plaintext data, do not connect.