Just put them up on the internet. That's the best archival method. Haven't you heard? Once it's on the 'net, it's out there forever!
Though seriously, film isn't as archival as people tend to think. The colors tend to fade. The film can melt, get scratched, grow fungus, get lost or stolen, etc. Your best bet for archiving is to store them digitally in multiple places. Have a copy on CD and another copy on the cloud somewhere. Maybe put a copy on an external hard drive or a thumb drive and keep them at a different location. Sure, formats change and old ones become obsolete. But programmers have become aware of the issues that creates and they've gotten really good at maintaining backwards compatibility with things. I mean the .jpeg, something still in use today, was invented over 25 years ago and shows no signs of becoming obsolete. Furthermore, if you're that worried, just save them as a bitmap. Those are uncompressed files that are about as basic as they come. They're basically just a record of every pixels color and location. A million years from now, people will still be able to make sense of them. You could look at the code and rebuild an image without a computer if you needed to.
So save it digitally in multiple formats in multiple locations, and it may outlast humanity.