If your digital camera comes with a mini remote for recording and snapping photos, you can make cheap backup remotes in case it gets lost. If you do a lot of travelling or outdoor photography, youtuber thefrugalfilmmaker suggests you buy some cheap mini universal remote controls that can learn all the functions of your camera's current remote. That way if you leave it somewhere or drop it in a river you still have a backup waiting for you. If you're not sure where to get some, he recommends this DC 3V Mini Learning Remote Control RM-L7 model on eBay because it takes AAA batteries instead of button cells. For about $US4 ($5) a pop, you can make sure your camera is always remote controllable.
Tip: Backup Your Camera Remotes! [YouTube]