Here is a list of the equipment I generally use:
Bike: I have an extra old (1998), extra heavy (I relish a good workout) Rocky Mountain DH Race. It has dual suspension which is quite nice floating down some of the fire roads, but I’m quite sure it isn’t worth it to lug that extra few pounds up hills, over logs and roots and through mud bogs. However, I haven’t gotten around to upgrading. I’ve had suggestions that I should consider a 29er, specifically one of the Specialized. As long as the bike is in good mechanical condition, and fits your body size and style, you’ll do fine. After all, it’s the engine that counts.
Bike repair: Multitool with chain break, allen keys, wrenches, screwdriver. Patch repair kit with 3 tire levers and extra tube (make sure the valve type matches your rim. You’ll surely curse the day when you realize a Schraeder valve doesn’t fit a Presta rim). Make sure you are able to repair a tube at home before you try it in the woods, raining, tired, etc., etc. Pump that will fit your valve.
Food: I carry and eat about the equivalent of a granola bar (200 calories) per hour at least, plus an extra 2 hours of food.
Water: At 20 degrees celcius, I use about a water bottle (24 ounces) every 2 hours. I carry a couple water purification tablets, just in case.
iPhone: I’m sure any smartphone with gps capabilities is sufficient. Cell service is generally not available in the valleys away from paved roads, but usually available on mountain tops. Most importantly, I use my phone as a gps device, and as a backup camera.
Camera: Depending on how far I am riding / hiking, and the potential pictures that could be taken, I might only travel with my iPhone. However, I really don’t like the picture quality from such a small lens. I also use an Olympus Stylus Tough (a waterproof point and shoot), a Canon S120 (a very decent point and shoot with quite a large image sensor, thanks to Faithie!), a Canon Rebel xTi (an older model digital SLR which takes quite nice pics and don’t mind if I get it banged up a bit), and a Canon 6D (for when I am out principally to get photographs).
GPS: There isn’t a much worse feeling than getting lost as the sun is setting. Gladly, I’ll trade a 1:50,000 topo map plus compass for a decent GPS any day. I used to use a dedicated Garmin Etrex unit, but nowadays with smartphone technology, that isn’t necessary. I haven’t tried any other gps apps other than Gaia GPS because this one does so much. Everything I want plus more. This app allows me access to multiple map layers including the entire set of Canada topographical maps. Even more useful are the Open Street Map and the Open Cycle Map. I will download a mapset before I go out, and this map will continue to be available once I am out of cell service range. The gps app will then track my location onto the map using the tracking satellites, and will automatically download my track. I am able to plot waypoints (like trail junctions or picture locations), and all this information is stored on my phone until I get home and can download the track as a .gpx or .kml file, which I can then load onto my webpages, and become available for anybody reading the description to upload that track into their own gps device. The Open Cycle Map has exquisite detail. Even when travelling in Mexico, Hawaii, or Turkey, I don’t need to worry about getting lost, even on rather remote hikes. It’s probably the best $10 (I think now $15) I’ve ever spent.