I have never heard or known JPEG's to loose quality with time - only with direct manipulation, such as post processing.
I do agree though, that TIFF is a much better format to store originals in. I use JPEG to send out samples to those who need to see items of interest. Storing the raws help, but those formats will go away with time and the retirement of the camera in question. TIFF has been around for 20+ years and is an ITU standard (See T.38 spec for fax), as well as an accepted universal archival standard.
However, the original poster was asking about digital storage options.
Several things to consider:
1. You can store JPEGs, TIFFs, or any other type of digital data onto a media with lossless compression and suffer no quality degredation.
2. JPEGs are already "compressed" with respect to redundant data contained within the format. The reason it is "lossy" has to do with the fact that in creating the JPEG, the algorithm chooses to keep what it considers to be important pixel data and throws away non-important pixel so that (depending on the quality setting - ie: Photshop) you may loose 10% to up to 90% of the originally captured digital information in the process of creating the image in that format. Your eyes still see a nice picture, but there is nothing there in the file but "essential" data used to create the photo. Post Processing the image again will cause another loss of information and detail as the same alogrithm is applied each time.
So, when you attempt to compress a JPEG, you get little to no space savings on your media as there is little to no redundant information to be tokenized by the compression software - unlike BMP's where I have seen compression ratios run as high as 100:1.
3. Any long term digital media that is of archival quality will suffice to store images. The National Archives in Washington DC still uses tape as a main source of information storage. They have been evaluating the use of DVD media for some time. Back in 2001 they concluded that tape still had the lead with a 20+ year life span for premiun quality media stored under the right conditions. However, I don't have any friends who have 9 track mag tape drives, so DVD/CD makes a good next gambit.
Realistically, when stored properly, a "Lifetime" DVD (such as Verbatim) should last you between 5-10 years before the organic dyes in the media degrade to the point you risk loosing you data. The actual lifespan is dependant on a number of factors such as temperature, humidty, storage, and most importantly - exposure to light. Kept in a light proof container, upright, at human comfortable temperatures (55-75 F), with low relative humidity and played in your drive very rarely, you should see the long end of the lifespan.
Another popular option is the use of external hard drives. This is not a bad option, if you plan to store the drive away and not keep it spinning all day long. Since it is a mechanical device, it has a lifespan. A good quality drive these days has a MTBF rating of 1-2 million hours of operation between failures. To out it into context, if you started a drive like this up and let it operation contiously, you should see about 4167 days of use, or a smidge more that 11.4 years (given 1 million hour MTBF).
Conclusion:
I've only touched on a few thinggs here, but whatever media you decide to use, I would highly suggest making sure you backup your photos onto multiple media (either all CD,DVD, disk, tape) or a combination thereof, to insure that if you have one that fails, there are other copies to be used that work. I would also suggest storing one or two copies offsite, incase you house burns down or other calamity - so you don't loose the irreplaceable.
...Paul
jpg is said to lose quality with time. for this reason it is not
advisable to store in jpg
best to store is tiff format
raw should be stored as originals archive
just my personal opinion
cheers
