USB memory, laptop and PDA keep our data but it’s very easy to loose them.
Encryption is the answer to this matter but, if you (like me) use different machines with different operation system, you have to find something that gives you the possibility to encipher/decipher your data using something that behave in the someway on the different operating system you use.
Truecrypt is ‘that thing’: it’s available for Windows and Linux and it ciphers your data using AES-256, Blowfish, CAST5, Serpent, Triple DES, and Twofish. Data ciphered can be read easily on the different platforms that support Truecrypt.
Developers are planning to release the software for MacOS X too.