Well, USA was once famed for it's liberty but it's liberty and freedom is all spent and squandered and the trust have been all used up. Indeed this is what they call liberty and freedom... hmmm....
This age, there is and already is absolutely NO LIBERTY OR FREEDOM. Those with a dream of liberty and freedom is as good as a wasted dream or either, you really have to fight an upwards stream and bring about a revolution of culture to bring back liberty and freedom and to secure the hearts and trust of people.
Anyway, back to topic, it looks like those customs officials would make it a headache for you when you cross into their borders with electronics. This is not confined to just the USA and Britain, this is true to most of the countries these days when they are so paranoid about the content you bring in inside your electronic device.
Encryption wouldn't work anymore since they would give you a bad day, 'torture' or literally torture you until you decrypt your stuff and surrender your passwords and contents.
As Schneier said, it's best that the data or information is not there and not available on the machine. So get yourself some data shredding tool like AxCrypt or other cryptographic software that can safely shred your files to leave no trace for recover. If somethings' not existing, then no one knows... the safest bet.
I thought of another way to allow you to use a computer without bringing in any machines. Get yourself a Linux LiveCD (this works for Linux users) and that's all you need. Find a computer and boot from the Live CD (don't install it !) and just use the Live CD to connect back to your company's VPN (make sure the VPN has SSL protection) and you can start accesing your company stuff.
Another way is not to bring anything and don't do anything... that's the best thing there is...