Apart from the showmanship factor for both devices .. on a serious comparison note - we have to give Apple the credit for raising the bar of what a Cell phone ought to be and for the excellent UI.
But having said that - between the iPod Touch and the Nokia N800, the N800 beats the touch out of the water.
In fact I would compare the N800 with the Iphone - where excepting the GSM phone , the Nokia IT excels in every other department.
The Nokia IT (N800, N810) can do Voice theu Voip excellently - Skype, Gizmo, Gtalk, all supported.
Connectivity they Wiwfi, And Bluetooth and USB cabling (Ipod touch only does Wifi and has a crippled Bluetooth)
Open platform on the Nokia IT - much more open than Appale can ever make the Iphone or Touch to be (SDK or no SDK)
GPS and hardware keyboard on N810 - well even though thread is about N800, the N810 should also be considered.
Excellent battery life of Nokia IT's - I have it running and connected to home Wifi for 2 days running (always on state).
Some software does the Iphone UI experince vis-a-vis Intertial scrolling etc (its not device centric though like the Touch - Apple beats the Nokia IT's here. Many apps on Nokia does have finger support though.
(check out a demo of Canola to see what I mean - http://marceloeduardo.blip.tv/file/541526/)
Browser experinece is the best - Flash support included (and not only UTube like the Touch or iPhone).
Memory expandibily theu SD/MicroSD card support and slots (2 in N800, 1 in N810).
Replaceble battery in Nokia IT's.
Larger better screen on the Nokia IT's (I held my N810 beside an Iphone and the N810 certainly looks better).
Inclusion of external speakers on the Nokia IT (in fact I play songs off the N810 on my car while driving with GPS on ..dont know if Touch has it)
Feature for feature - the Nokia IT's are a much better deal than the Iphone or touch.