Ok. I'm a CO guy, visiting the UA section today -- given that it sounds more and more like UA will become my new favorite airline.

Can someone provide me the basics of the UA mileage plus program?

On Continental:

25k = silver
50k = gold
75k = platinum
platinum + $30k spent = presidential platinum (new this year -- give access to president's club)
100k gives 4 one-way upgrade certificates that can be used even internationally (new this year)
Upgrades for platinum domestically are generous, get processed automatically, starting x hours before flight (sorry I cannot remember).

How does Mileage plus compare?