To add to the above.

At 120k and at 160k Platinum members of WorldPerks have the opportunity to choose 2 one-way system-wides on any fare. Registration was required in 2007, not sure what 2008 holds in store. Not as good as UA or AA, but better than nothing.

Additionally Platinums can upgrade one other person on the same itinerary domestically automatically when the EUA runs.