Is there any way to make iphone accept outlook calendar invites?

Whenever my assistant sends me an invite to my phone, the phone doesn't recognize that it is an invite email and won't give me the option to accept it or add it to my calendar on the phone.

I can't believe the only way to have an up to date calendar is to sit at a desktop and accept, the sync or have her enter it into a mobile me calendar.

Am I missing something?

Perhaps it is time to shift to iCal - i got rid of all MS stuff in 08 and iCal and iPhone play nicely

I would happily but my office staff are all on ms except for me and one other person. If ical can accept an invite why can't iphone?