You should try the likes of Gravity or Google Maps or the thousands of other cross platform apps.
Gravity is btw the best twitter (and Google Reader) application on any platform. I prefer it to Tweetie on my Mac even.
Google Maps on S60 is nice too (although I prefer Ovi Maps and its preloaded maps some of the time - hey, choice of free maps apps eh?) and we don't have to wait for Apple to update their version to get the latest Google features. v3.3 added syncing of favourites.
I'd add Nokia Messaging for Email http://email.nokia.com/ It's a good mobile email program (easily better than iPhone's email app) and Nokia's push email service is both FREE and quicker than even my own mail servers at pushing IMAP IDLE mail at my Mac. Usually my phone beeps before my Mac gets it's mail.
I'd also add the rock solid inbuilt SIP client but that's not really a fair fight v the iPhone is it.
Sure, they aren't as flashy but they just work.