Unfortunately, the OCR client is only available for Windows at this time.
To use the newest client, you only need one files:ppaocr.exe, in a zip'd installer.
The archive contains an installer, and a .msi file. Open it and run setup.exe.
As with any downloaded executable, you should virus scan it before
running it.
Run ppaocr.exe to open the OCR capture client. You can run it
from the Start menu easily enough.
To collect market data, open a market information screen (in the market, or from a shop, ship or stall), switch to the OCR client, and hit 'Capture market data'. The automated capture should switch to the Puzzle Pirates window and page down through the shop data. When the client is finished reading the data, it will beep and (on WinXP) move back to the OCR client window. Select 'Upload the data'.
To collect bid data, from the market harvest bidding screen select each commodity in turn and
hit Ctrl-C. Return to the OCR client and make sure it lists all of the
commodities. Select 'Upload the data'.
For both types of data, once uploaded you are prompted to select which island the data came from. The server will make one or more guesses; the first guess is usually correct. When the correct ocean and island are displayed, hit 'Select Island'. If the ocean the data was collected on isn't listed, enter the ocean's name and hit 'Add Ocean'. (Note that German language oceans are not supported at this time. Sorry.)