iPhone as PDA? Enter data on phone directly?

OK, they just knocked $200US off the price of an iPhone 8GB. So now my only hold back is this: I have a Palm Tungsten T3 which I use with Mark/Space Missing Sync and iCal. I like being able to make on the go calendar entries throughout the day at work on the T3 and sync it withiCal at night. Thus, I can edit those entries in the evening, delete them, etc. So the question is, can I make calendar entries during the day on the iPhone with it's keyboard and sync with my MacBook at night, thereby syncing the two? Or, can I only add items from the Mac and push them to the iPhone, much like the calendar function on the later generation iPods? Any thoughts? Thanks!
-Dave

Yes, the iPhone allows calendar/contact entries directly on the device to sync back to your computer.

Thanks Dimitri! Guess I have no excuses now, unless I wait for iPhone 2.0 LOL
-Dave