The issue of backups can be somewhat vexing. First, you cannot burn archival CD's on a PC due to the PC burning software's inability to burn at 1X or 2X speed.
Pit depth is the Holy Grail of CD backups. I have hundreds of 20+ year old CD-Rs which are completely fine and readable right now. This is because 1) the quality of the CD-R is not of "discount store" but archival quality (over $1 each when I bought them so long ago) and 2) I never burned faster than 2X and at 1X as much as possible. Glacier slow, that is, but those discs LAST.
Due to the idiotic "need for speed" in CD burning, the PC industry put out an official edict YEARS ago saying users SHOULD NOT ARCHIVE TO CDs due to near term loss of data issues. Burning fast = shallow pits = near term data loss.
Now, with modern cameras spitting out 20-75MB files PER FRAME, CDs are no longer valid. Neither are DVDs.
The good news is Blu-Ray, by its very chemistry, is relatively archival from the get-go. Only time will tell, though, as it is a new medium.
Hard Drives are quite cheap, but take caution: certain hard drives are designed for 50% on, 50% off (as in shut down,) daily. These drives also fail quickly overall.
Better quality hard drives are designed for mission critical applications and 24/7 operation. This is the way they should be handled. You turn them on. You do not shut them off. Why? Because THE WORST thing you can do to a computer, and especially a hard drive (the heart of the modern computer) is to turn it on. This is the wear and tear. You can expect a good hard drive to last at LEAST a decade of 24/7 use. Now, make sure you feed it good, protected (online UPS best, regular UPS okay) power.
Better still is to use a RAID (R_edundant A_rray of I_ndependent D_isks) but this often involves an IT department, especially on a PC. The answer: Drobo.
http://drobo.com/These smart RAID systems (choose RAID Level 6 which allows TWO drives to fail simultaneously with no loss of data) and just go big with 3TB drives. The RAID implementation and maintenance are hard-wired into the box. You need do nothing.
The good thing about Drobo is that you CAN have RAID "sets" which can be shuffled in and out of, and between Drobo boxes, if you keep the order of the drives correct (by numbering them.) Keep in mind you can lose TWO DISKS under RAID 6 with no loss of data. Still be careful when shuffling disks.
The online services are great if you do not shoot much, or just save your final edits. These services would not allow general backup if you produced monstrous amounts of data all the time. Unless you are Steve Jobs, Warren Buffet, or Bill Gates (who uses Iron Mountain for archival storage.)
http://www.ironmountain.com/All of this, including this thread, will be moot in a few years when carbon storage makes it to the street. Petabytes of archival storage is the smallest size predicted. And it is archival as the inert carbon containing the data. No chemistry to fail, no magnetism to weaken, no metallic disks to corrode. I can't wait.