Keep Good Records:
1. Record in detail what equipment you own- brands, models, and serial numbers are a must.
2. Take photos of the gear you own.
3. Store this information in a few safe places. Keep a copy for yourself, in an at-home safe or safe deposit box. Give a copy of your inventory to a close friend or relative. Or, send the info. to yourself through email.
4. File receipts from purchased gear, and any paperwork proving ownership such as registration and/or warranty cards.
5. If you are traveling with gear, make a list of what you're taking with you, and keep it in a separate place from your gear, such as in your wallet.
1. There are multiple ways to mark your gear such as engraving, permanent markers, and stickers. The issues with these options are: stickers can come off, and engraving and markering can bring down the resale and/or trade-in values of your equipment.
2. Metadata- If you have a D-SLR with one of these options, use it. Sure, a thief may know how to delete the info., but they also may not. Set your copyright and contact info. in your camera menu.
3. Keep a business card (slightly hidden) in your camera case. If you loose the case, or if it's stolen and then ditched, someone will hopefully find your card and know who to contact.
1. If you own a lot of gear, or own expensive gear, insure it.
2. Keep your gear out of site and locked up when it's not on you. Never, ever leave your stuff in the front or back seat of a car where someone can spot the camera or bag. If you're putting gear into the trunk of your car, do it when people are not watching. Some cars also come with a trunk lock so that if someone breaks in and they don't have the original car key, they can not pop the trunk.
3. Don't show that you're traveling with a lot of gear. Be discrete, look like you know what you're doing. Keep a low profile.
4. Travel light- don't take everything you own with you.
5. Keep your camera bag closed up at all times, and remove any long zipper pulls. Wear your bag in the front of you instead of slung behind your body. If you have locks, keep your cases locked, or invest in a specific bag or case just for traveling that is secure and doesn't scream "camera bag" like your day-to-day bag may.
6. Pay attention at all times to where your gear is. Keep it close and don't leave it unattended.
7. Back up your photos on multiple memory cars. If you're traveling with an external drive, keep it in a separate place from the rest of you gear so you don't loose your photos as well as your gear... those can't be replaced.
If your camera gear ends up in a disaster such as fire, flood, etc. the first thing to do is to take photos of the ruined gear (if you still have it), and alert your insurance company. Having before and after photos, as well as gear lists and documentation will make the insurance claim process much easier.
If your gear is stolen, first file a police report. Then, alert your insurance company and get the word out for people to be on the lookout for you gear. Tell other photo friends and colleagues. Alert used camera dealers. Keep an eye out on Craig's List and Ebay. Most likely the thieves will try to resell your gear, and you will have a much better chance of recovery if you have proper documentation and get the word out to the appropriate places.
If you have insurance questions, this is a good article to start with.