I'd highly recommend heading out to your local camera store for an evaluation - take a CF card with you. If you don't have one, you're going to need a compact flash card with either of these cameras when you buy them.
Heres the differences of why I went with a D70 rather than the 300D (at the time, but still apply to the 350D mostly):
* feel of the D70 body - it's a personal preference thing, but the D70 just has a better presence and feels more robust... and I've tested this accidentally. It still works, the lens hood isn't looking real good after the mishap but everything else is just fine.
* flash sync speed: 1/500 (D70/s) to 1/200 (350D)
* flash system - the wireless iTTL with the SB600/800 is great. The Nikon CLS (Creative Lighting System) is a hidden gem of the Nikon flash system. Even better should you upgrade at a later date to a D200/D2 series.
* kit lens - the D70 kit lens is AF-S SWM or in Canon speak USM. The 18-70DX is a winner for the price. Compare the weight and build of the 18-70DX to the Canon EF-S 18-55. I cant remember exactly, but I don't think the Canon kit 18-15 is USM.
* the controls just made sense (TM) on the D70. I also prefer the display layout with the info screen on the top, main display on the back.
* metering - spot metering on the D70
* lens compatibility for my limited collection of Nikon MF lenses.
The choice to go Nikon or Canon wasn't one of those religious fanboy things - I have fully manual gear from both manufacturers. I couldn't use my Canon FD mount lenses on any EOS digital gear though.
6MP vs 8MP. Not worth getting all concerned about. It helps sell the 350D in Harvey Norman, Domayne and Bing Lee.
I recently had the choice to purchase a D2h (4.1MP) or D200 (10.2) for around the same price. I purchased the D2h, and in some ways the image quality beats that coming out of the D70 using the same lenses (this is not to say the D70 is rubbish, it's just that MP doesn't necessarily determine image quality).
The marking puff re MP is everywhere - I recently was in a cafe slurping ny coffee with the D2h on the table after a photo outing. Some guy comes up to me and we have a discussion about photography for a while. The conversation included:
guy: "hey, thats a big arse camera! How many megapixel?"
me: "four"
guy: "that's pretty crap! My Kodak easyshare xxx has 8!"
me: "it's a PJ/sports camera. It'll have 8 frames off by the time a compact is ready for its first".
guy: "oh.."
ISO 200 vs 100 - I've never really seen ISO 200 as a limiting factor. There's a post on this forum where Killakoala talks about the native output of a CCD/CMOS.
The Canon IXUS 60 as a base ISO of 80. While being a very good compact, probably doesn't compare with a DSLR for long exposures.
Another thing to consider would be the access to Nikon bargains that are made available through our resources here.
Whatever you decide, make sure you physically handle the gear before buying - it may swing you one way or the other. It's no good being great on paper, and a
POS to use in the field.
Neither the 350D or the D70/s are bad cameras - they have their differences and some of those differences make for a better match for your needs.
edit: whoops - post cross over. bleh, some it might be relevant for future searchers.