We have been using iPhoto for our photo management system. This has worked pretty well on our macs, even though I had to take some steps to have access to the photos on our multiple computers.
Now that I am using Ubuntu, I want to find a way to share these photos on all of our computers. I started to copy all of these photos onto our network attached storage drive, but I only can modify the photos in iPhoto, otherwise iPhoto gets out of sync.
We could upload the photos to our gallery installation, but our VPS only has 40Gb of disk space. The online photo sharing sites seem to be the best solution. I had downloaded the Picasa Beta for linux, and it looks like it could be a good replacement for iPhoto. Also, the Picasa has the ability to integrate with Picasa Web Albums. Unfortunately, our iPhoto library is 15 Gb. This would cost us $75 a year to host our photos.
It is looking like flickr is going to work for us. We already have a flickr Pro account, so we have unlimited space and bandwith. This will allow us to access the photos on any of our computers. The one downside is that there are no application, that I know of, that makes flickr photos appear as local files for editing.
So now, I am in the process of uploading our photos, and keeping them private. This will also allow us to share these photos with family members.