Unlike Bitcoin, Nxt presently relies solely on brainwallets as the means of user authentication. There is no "cold storage" alternative offered.
Type anything like
NW948YN3V95YN0PWS93498934N376N095HG857028MEOAWMFYCNOQA789O837QY8
Save it and use as a cold storage passphrase.
The account (16025050820116515852) has 0 coins. Wait a few days and we will probably see something there lol!
We should fund all the accounts of known passphrases with 1 NXT to prevent the use of it.
How about kill two birds with one stone?
Create a script to send 1 NXT (with 1 more NXT as the tx fee) to the addresses created by the dictionary from the unclaimed account every minute. The tx fee can help to increase a little bit incentive of mining.
Moreover, this can be a good penalty to those unclaimed owners. This is a great idea!