In a recent blog post, I made some comments about the JPEG 2000 file format. Saving files in this format was supported with an Adobe Photoshop plug-in up to CS3. Subsequently, the plug-in was only limitedly available. The latest version of Photoshop CS6, allows saving a file in a JPEG 2000 format.
JPEG 2000 is a lossless JPEG file format. Another more popular lossless format is TIFF. The file extension for JPEG 2000 from Photoshop is .jpf
For example, Photoshop Elements 10, the latest version will not open a JPEG 2000 file in .jpf format, neither will Google's Picasa. This format is also not recognized by the current version of iPhoto. TIFF files are all supported by all of these programs.
You may want to read more about JPEG 2000 and other file formats before selecting any one of these formats for archive purposes. For a lossless format, TIFF files are currently the most supported.