Del had asked this question on the MacinTech email list -- I thought it would be helpful to other members to post this Q&A here for future reference. If other members have related suggestions, adding a comment to this thread will keep all suggestions in the same basket 
Fellow sufferers of Macphilia,
iPhoto is kind of large to think of backing up to iDiski. Is there anyway to easily backup selected photos in iPhoto?
Del Knudson
Here's one easy method to backup to CD or DVD:
A similar method would be to insert a blank CD or DVD into the drive, then drag and drop the selected images from the iPHoto Library view directly onto the mounted disc. The approach is essentially the same.
The advantage of this type of approach is only the selected images are burned verses burning the entire iPHoto library structure
Remember -- the image you drop onto the Burn Folder needs to be in a file format that the recipient can read. For example, one wouldn't want to burn a PSDi (PhotoShop) image onto the Disc if it was intended for someone who doesn't have PhotoSHop
The same method could be used to drag and drop the selected images to an external hard drive, internal hard drive, jump/USB drive or a dot.mac iDisk.