Question about handling 'new items' per user...

Hi,

I'm building a little app that tracks shipments - each user is
associated with a role and that role has_many shipments.

I'd like to add a feature that displays new shipments since the user's
last login. Here is my guess at an implementation:

* create a column in the users_table last_login that timestamps the
users last login (duh)
* when the user logs in, the previous last_login is saved to a
variable (instance? attr_accessor?) then overwritten with the current
login timestamp
* @unseen_shipments = Shipments.find(:all, :conditions => ["created_at

?", last_login])

All advice and criticism is welcome.... thanks!

SH

Any suggestions?