I've just did a quick search, but have been unable to find anything official (i.e. direct from a Nintendo source) that states absolutely that both cameras are 0.3MP. I seem to remember an interview on the Nintendo website, I believe from the DSi "Iwata Speaks" series, where Mr. Iwata says 0.3MP in regards to the camera(s), but I remember thinking it was unclear from the context whether he was refering to the resolution of both or only one of the cameras. Maybe a future translation of these interviews on the NOA website will clear it all up.

Ok, I'm not sure if there is a flaw in my method, but I went ahead and did it anyway, so here are the results.

For both images, the resolution in Photoshop is the same:
Width: 640 pixels (22.58 cm)
Height: 480 pixels (16.93 cm)
72 pixels/inch

Inside camera:

Outside camera:

These pictures look better than I thought they would. The DSi slowly creeps towards a must-buy for me with stuff like this.

Both seem the same, thanks ramuji.

Here's an excerpt when the DSi was announced:

For mobile phones and digital cameras, manufacturers have been increasing the number of pixels in order to appeal to the consumers. However, we have taken almost the opposite approach. We cannot boast about the resolution, as the camera for DSi has a 0.3 megapixel resolution.

http://www.nintendo.co.uk/NOE/en_GB/news/2008/nintendo_introduces_dsi_9691.html

Well 640 X 480 is indeed 0.3 Megapixels....but it does still look very clear. Kind of shows what I have been saying for a while.

The number of Megapixels is pointless if the lens isn't good.... and unless you intedn to blow photos up past A4 size, you should not need more than 4 Megapixels.

For standard photo size like you would get from a normal camera, 2 Megapixels is fine.

Of course you do need more if you are going to photoshop things and zoom in on parts, but the current standard of cheap digital cameras seems to be around 10MP, which is more than enough for anyone.... the limiting factors instead become the quality of the lens, and then the quality of the printer you use.

Not bad at all. Im sure pro photographers will rip on it, but for the average person, thats not too shabby

Yeah babe, best performance I've seen on a 0.3 megapixel camera!

very true.

you also need to have good demosaicing or else your picture turns to crap and looks blurry. Odds are the iDS is much better at reconstructing the raw image than most cell phones.

Heh heh, not anymore.  I had 2 jobs for years, and blew all my money on the camera and a trip to japan.  I've been broke as a joke ever since.

That's an impressive, er avatar you've got there.

I have to admit, pink really suits you.