Yeah, but that will only work if you have:
1. good signal
2. really unlimited data plan.
Personally I don't see reason to backup few small files, since you can get SD card for cheap and store it on the phone memory and SD card as backup. I'm talking for example about being on vacation and actually running out of memory due to picture and video taking, where you need to offload gigabytes of data, where good signal and unlimited data could be completely out of question. Actually I may be taking trip to China this summer and could be facing this particular issue for real and any cloud type solution is not going to work at all. On my home turf I have access to computers daily, so again cloud services are pretty much useless, even if I had unlimited data, which I don't. I know Google and others are trying to sell us on cloud storage solutions, instead of physical storage, but in certain situations above limitations can not be overcome.