You can do the photo uploads (& sync of course) with Dropbox as well if you have chosen to upload photos in the settings. This feature was added last year and it's free specifically for photo uploads (adds any space used for photos to your pre-existing Dropbox limit) as opposed to Picassa which is subscription based above the 1 gb limit.
Dropbox is still offering free space for photo uploads according to their "help"...
https://www.dropbox.com/help/287/en
It also allows you to use the Google photo uploads feature to Dropbox, more details here.
https://www.dropbox.com/help/search?...g=Photo+upload