For business I use Safestick which is a proprietary encrypted memory stick with onboard AV etc, although these are expensive, we can manage these sticks from a central console which is useful for keeping track of who has what data.
For my own stuff I use Truecrypt to create encrypted containers on a stick. The good thing about this is that you can use them on any machine, you just open them up with the credentials you have created. With other encryption solutions the stick will only work in conjunction with the machine with which you encrypted it and to make sure you could recover the data in the event of the machine going belly up you need to back up the keys, which is a bit fiddly.
I'd be reluctant to store anything in the cloud.