Just keep it in a lock case. This solves the problem of Evil Maids, but not of Evil Maids-financed-by-the-NSA-with-lockpickers. I have to imagine that if those types of people were after your encrypted info,you'd know and you'd probably keep it handcuffed to your wrist.

I usually just keep my data on a USB key and then buy a brand new laptop from a random store every time I want to access it.

Oh rly?

please, think of james bond! how could he drink a martini gracefully when a suitcase is chained to his hand?

james gracefully holds cocktail glass with both hands? now if he had other hand around woman's waist, that I would understand :)