Encrypting Data in External HDD???

hi guys
i am gonna leave my home and stay in hostel for my higher studies.
i am having all my data in my external HDD.. including IM and pron

how can i hide or encrypt data in my external HDD ..
is ther any particular software for that..
plz give me ur ideas..

thanks...

well i usually use TrueCrypt and its free

Theres 1 where not even Gov't can hack it , its like 1024 bit encryptionn... GOOGLE