Question: I have AAO110 (512ram, atom 270N)
What is best version of Ubuntu, if i need just web? UNR 10.04 was almost fine, but i wonder if there are better options now.

browser, blue-tooth, WiFi, long battery, no extra elements on screen (e.g. not like in Unity) while browser opened

Answer: 
I would suggest [Kruptos 2 Pro encryption](https://kruptos2.co.uk) software if you want to use your files on Windows, Mac OS and Android. I would suggest Kruptos 2 Pro is best fit along with any cloud folder integration. Kruptos does support USB drive as well. You can use simply right click context menu.
The problem with free solutions is that apart from a few, most of them are usually not well maintained or well supported. You have to wait for compatibility updates and bugs resolutions. It is also better to go for container encryption than drive or disk encryption, specially for external drives, as they are more flexible and easier to manage. If you are willing to spend a little, I can suggest **BestCrypt** containers. They are supported on Windows, Linux, Mac and even Android with a number of algorithms. Instead of encrypting your USB, you can create a container the size of your USB, external hard drives etc. and access them on each platform.