This is actually my response to a yahoo answers question.
I just got my Nokia n97 and as an Iphone 2G and 3G user. I wanna go over some aspects.
N97 is new and not many applications and games developed for it yet but it already has large list of existing symbian applications. It has free download application already and Ovi store. Filled with some nice apps already in 1 week time. Compared to the appstore which happened 1 year later (copy catting the installer - jailbreak / hack - idea ) and 1 year old. Do not expect dumb applications such as bill divider or metro maps, Nokia will say you have a mind and calculator. Iphone users are mainly dumb - me too - it spend 1 years before you can even use a IM application on it. Iphone came to this point in 2.4 years while Nokia - Symbian phones did everything for years.
As a user development part should interest you also, why? Because apple sells the Iphone SDK and training, meaning you need to pay apple in order to develop some application or game for it! While symbian is open and used for years. Anybody can do anything with it, if they set their mind to it. If you really want touch and view experience I suggest you to wait 2 more weeks and get the HTC Hero Phone. It is bringing the Android OS - developed by Google for Mobile Devices - which beats the crap out of Iphone experience. In couple years Android and Andro Phones will grow much more than Iphone closed SDK.
Touch screen is pretty accurate. You can touch with anything unlike iphone you are suppose to touch with your bare skin. Comes with its special pen, which is pretty good in handwriting. Makes writing a lot faster. Supports double clicking. Sliding, scrolling is not as fancy and smooth as Iphone. You are suppose to point click and scroll like in PC environment, not with the whole screen. N97 keyboard is nice and enough spaced to let you write fastly. Symbols and numbering options are not user friendly as IPhone's though.
Nokia comes with already built in office, pdf, zip and flash support. You can see and use flash websites which is kinda important for me.
Nokia doesnt have a graphic unit as powerful as Iphone, so you cant expect that much of fancy 3D games.
You can only run 1 application at a time in Iphone which really sucks. Meaning if you are chatting you can not check your new mail and continue or visit a link and go on. They tried to make a push service now but it is useless except for chatting. You still can not pause your game, go to your email reply and continue. In Nokia you can run and switch between any applications anytime you want. It also supports background applications.
Nokia have its emailing application with the "Messaging" center which includes text, mms and every messaging all together. Emails are not well displayed as Iphone. It is a non-html email client basically. But you can view the html format in browser. Iphone email client is much much better in this point of view. Safari scrolling and zooming options and speed is better than Nokia's browser also.
Phone features, well Nokia is a complete phone while Iphone is a calling, texting, ipod included smartphone wannabe. If you use the phone as a PHONE do not go for Iphone.
Nokia comes with built in gps also, signal strength and quality is better then Iphone. Nokia includes Integrated online - offline maps and routing for all the world. You can go for Tomtom for mobile also.
Reception, Iphone reception really really sucks. Wifi reception also. Nokia celluar reception and wifi is more powerful as usual.
Camera, well of course 5mp HD video recording with bluetooth support Nokia is the winner.
Battery life, you will need to charge your iphone every 16 hours or so if you play,chat maybe in every 6-7 hours. While Nokia goes for days. With Iphone you can not have a backup battery and after 3-4 months you will see that your battery life is over. You can not change the battery too of course.
Yesterday I wanted to use Iphone as GPS and after 40 minutes drive battery was drained of course. Hooked in the car charger and wanted to use GPS but, King Iphone said its too hot to run while charging and using GPS! in 20 degress. Left me on the road clueless without warning!
Final reason I got Nokia is, I switched to a pay&go SIM card and you can not switch off the damn GPRS in Iphone! If you enter wrong connection settings to switch it off and prevent from draining ur balance, it keeps trying and trying until battery is finished. You charge your phone and after 4 hours its gone without even opening the screen.
With Iphone you are bound to use the iTunes and your library or pc to transfer your songs to your phone. You can not hook up to your friends pc and get some songs or transfer your songs back when you lose them at your pc. After 3.0 and some applications capacity goes to 5GB for you to store your music. You could not put ringtones legally until new releases and can not change messaging or email tone for example. Videos needs reencoding also.
Nokia is like USB pen drive. You have 30GB to fill in with Music or Video whatever you want. Built in FM radio, Skype and SIP support. Divx, Ogg support. Hotmail and Microsoft exchange boxes btw.
Iphone parts and cables peripherals are very expensive and rare to find as original. While Nokia are easy to find and much more cheaper. Iphone only uses 1 type of connection for everything Nokia uses global I/O connection types.
In short if you expect fancy looks, fancy web browsing, games and music for your own pleasure go for iphone. If you want to use it as a smart phone with tons of fancy features and expect high performance go with Nokia.