What we do is we just have the scanner hooked up to one of the print servers.

When someone on the network needs to do a scan, they walk up to the print server and do the scanning, saving the file to a local "scans" directory, which is shared on the network. Then they go back to their own PC and grab the file from the shared scans directory.

I figure that if you need to be physically standing by the scanner to put your photos in it, you might as well have the scanning software physically there, too.

If the community scanner is hooked up to your personal PC and you don't want to be interrupted for others to do scans, perhaps you should look at dedicating an extra PC to being a scanner server.