I'm pretty sure a S60 based phone has a webbrowser. Probably Opera.

VNC, while its crossplatform, its dogslow. Its a waste of bandwidth, WWAN or not. It will also need to be run over SSH. If you need remote access from NIT I recommend either SSH, or SSH + RDP, or NX (SSH + X11, compressed).

I suggest to think more through what features you need, and why you need them.

Don't forget latency of WWAN. If you want WWAN on a NIT, consider N810 WiMAX. If you rather prefer (also) UMTS/HSDPA a NIT won't cut it, but you might be able to combine it with a cheap phone, or maybe a good phone provider almost same the NIT does. The camera on the NIT isn't good, and standard the DAP functionality isn't that great either. A phone is normally 24/7 on, while the NIT cannot be.

My suggestion, for now: combine a cheap phone [maybe with nice camera, better GPS, WLAN w/packet injection) with NIT for UMTS/HSDPA, consider a N810 WiMAX, or buy one of the more expensive smartphones like Iphone 2 or N96. You probably won't need a NIT with either one of those phones.

Maybe its time to make a list of functions 'often available' on smartphones and similar devices.

* Connectivity (IR, BT, WiFi, GSM, GPRS, UMTS, HSDPA, WiMAX)
* Usability (touch screen, multi touch, functioning DE, customizability, and so on)
* Features (SMS, SIP, PIM, DAP, NX/RDP/VNC/SSH, camera, GPS, IMAP(S)/POP3(S)/SMTP(S)/Exchange, which webbrowser with which features)
* Source available? DRMed?

Maybe I'm forgetting something. Heck, there are so many options these days!