Inside the Users folder you will find a Shared folder.
Put your iBank or Quicken data files in there and when either of those apps are launched, point them to the data files in the Shared folder.
You should only have to do that once.
For Pictures, I'll assume iPhoto here, launch iPhoto with the Option key held down. iPhoto will ask for the location of the iPhoto library or if you want to create a new one.
Choose New Library and navigate to the shared folder. Create the library there. iPhoto will use that as the default library from then on.
If you already have pictures in iPhoto, locate the Pictures folder that currently houses your iPhoto library and pictures.
Open a second window and find the Shared Folder. Create a folder called Pictures inside the Shared Folder. Open that Folder.
With both windows open, the original Pictures and the new Pictures, select one of the pictures in the original folder. Hold down the Command Key and press "A" (no quotes). This selects the entire contents of the folder.
Hold down the Option Key and Drag the selected pictures from their present location to the Shared Folder. This will COPY all the pictures and the iPhoto Library into the Shared Folder. Using COPY here to prevent any loss should something go wrong during the move. (Power failure perhaps)
Once completed, launch iPhoto with the Option key held down and point iPhoto at the new location.
When satisfied that all is well, you can go back and delete the contents of the Original Pictures folder.
The launching of iPhoto with the Option key held down must be done on BOTH accounts.
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