Google announced on Google+ that you can now ask your Android phone to take a photo or a video by saying, “Ok Google,” then “take a photo” or “take a video.”
This will launch the Android camera app in the photo or video mode so you can quickly take a photo. I should note that there are other variations of the “take a photo” that work, such as “shoot a” and “take a picture” and so on. Google Glass has supported this since it launched, so it makes sense to extend this to Android devices.
Where this may come in handy for search is in the future, if Google extends Google Search mobile to handle, “scan OCR code” or “find products similar to…” and so forth.
Here is a picture of the new feature: