Prof. Dr. Ing. Christoph Paar wrote a paper about security issues in pervasive computing. His main question was if there are differences between security applications for LAN and pervasive networks. This way he lists some of these networks and states that you'll need not much fantasy to find possible security problems here:

- Security in process automation
- Security in RFID-logistics chain
- Security in mobile applications
- Security in cars
- Security in ad-hoc-networks
- Security in geo-information-systems
- Security for "wearable" computer
- Security in intelligent rooms
- ...

Some of the differences right now are that in a LAN you can install new software what is not that easy for embedded computer chips. These chips today do not have the computing power for complex encryption. Dangerous are attacks that use information about the energy consumption or reverse engeneering to get information about the encryption used. Because you can not change things backwards it's more important to build in security systems before components are delivered.
Interesting that almost 98% of 32bit-chips are used within embedded systems and only 2% in usual computer.

Prof. Dr. Ing. Christoph Paar is director of the Horst Görtz Instituts for security in IT and teaches Communication security at the Ruhr-university Bochum, germany.

via (german) Inside-IT