C550 photos (how many)

Just curious as to how many photos the C550 can hold.
You can apparently link the photos to phone numbers in your phonebook
so it will display the persons photo when they ring you, so it should hold
quite a few photos, right?

Does it store them to the SIM card or to the phone?
The guy at the Vodafone store said it can store 30 photos, but according to the
specs sheet I've just seen on the web, the phone only has 1MB of memory, so
I can't see how you can store 30 photos onto 1MB, even in VGA resolution.

I also downloaded the pdf manual and there is no mention of it.