In days gone by the only phone on my bike or me was in a plastic bag in the saddlebag, switched off, used only for emergencies. Now that I'm a rolling emergency myself, I carry in my shirt pocket an iPhone 4S, which has a good camera built in, so I use that. The iPhone is in a Griffin Survivor case (colour-coded to my bike!) which is water-resistant and proof against all other cycling hazards.
For a movie camera on my bike I have a Kodak Zx1 which is designed as a cheap sports camera, decently water-resistant for bike use, and cheap enough not to worry if you lose it, so I leave it sitting on the bike even though my gorilla has a quick release tripod junction that would make it cheap to steal if the thief knew how to operate it. The trick to using it, or any other cheap camera on a bike, is to provide a semi-stable platform by wrapping the legs of a gorilla pod around the handlebars or rack and then mounting the camera on the tripod. It's normally mounted on the rack as intimidation for idiots in 4WD who come too close behind me: "I got you on camera." Works surprisingly well. Not a bad camera for so little money, but it will send the obsessives among you, the engineers and the technofreaks too, up the wall because the facilities are so limited.
For a still camera I used, and still keep, a Canon Digital Ixus 300, pretty old now, and clunky, but I love it because of the zooming analogue viewfinder that lets me see what I'm photographing even in bright sunlight.
The reason I hate an Olympus D-720 I bought on impulse because of 10x wide to 20x zoom lens in a shirt pocket format is that in daylight I can't see a bloody thing on its huge LCD, and there's no analogue viewfinder.
For practical purposes, considering that I normally cycle in a party whom it would be rude to delay with trying to get the perfectly setup shot, the iPhone takes snapshots the equal of anything Olympus manages, and not quite as good as the Canon only because I had years to learn to get the best out of the Canon. As I said, I no longer carry the Canon or the Olympus on the bike.