Originally Posted by Helium3

Laptops can be a problem only if they have wireless capability.
This is also true for wireless PDAs and some other wireless communication devices.
It is unlikely that even these will interfere as they operate on a frequency far from the equipment used in aircraft with the exception of ADF. Primarily radio communication and possibly fly-by-wire components are a concern but you are unlikely to encounter a problem there either.
You may hear the effects if you ever use these devices near an AM radio.

I haven't put in .02 yet so I thought it only appropriate to pay my dues.